According to Alex Roberts on "Live Nirvana | Equipment Guide | Pat Smear," Kurt Cobain owned a Mosrite The Ventures Model Mark V in blue, which he acquired in 1992 while living with Courtney Love in Los Angeles. Unfortunately, a burst water pipe caused substantial damage to his belongings, including this guitar, which suffered severe water damage to the knobs and rusted electric controls. Despite the damage, the guitar was played by "Big" John Duncan on July 23, 1993, at the Roseland Ballroom in New York City for four songs: "Drain You," "Tourette's," "Aneurysm," and "Very Ape." Later, on September 25, 1993, Pat Smear played this guitar on Saturday Night Live after the band declined a Charvel Stratocaster for being "too metal" and opted to use the Mosrite instead.

Ricky owned only two Mosrite Mark V models that were seen live, as far as I've seen in many photos; this first one (Blue) and a later one (Sunburst.) The Blue one is the guitar seen on the back of the first B-52s album, and you can make out the "Ventures Mark V model" name on the headstock (even though it's a bit blurry) if you compare its picture to other examples of this same model.

It's not clear if Ricky used this guitar in the studio, although I can't imagine why he wouldn't have; it does sound to me, personally, like he did. It is confirmed that he used it live, though. You can also get very good shots of Ricky playing this guitar in several videos; the Private Idaho mime video (prominently shown in much of the video:) https://youtu.be/yXmnmvDl-ao?list=RDyXmnmvDl-ao

and the Capitol Theater 1980 live show in B & W (see 2:00 for a long shot of the whole guitar, or 2:18 for a close-up.) https://youtu.be/99OksEzoABU?list=RD99OksEzoABU

Although I'm not 100% certain, this could be Ricky's first Mosrite Guitar since it's so finish checked and battered and because I have a photo of Ricky playing it in January 1978. There's also no other Mosrite that appears on stage in that picture, but it's not clear when exactly he bought his other Mosrites.

This 1966 model was built in a short few-month window from roughly March through July 1966, barring outliers (I've seen a few that were from later, but very few.) See Max Katzenberger's serial number list for the model version, and if you want, check above and below for more details of model name confusion (which I'll get to in later paragraphs.) https://hang10.de/lists/mosrite-ventures-2-model-mark-v-serial-numbers/#vbody

This Blue few-month version differs from Ricky's Sunburst Mark V in how the truss rod is located; here, it's at the Body End of the neck, and not at the Headstock end like on the Sunburst one Ricky had.

It has been said that Ricky owned a Black one, but that's from a video with bad coloring where he played his Blue one in Later 1978, supposedly October 1978: https://youtu.be/n4QSYx4wVQg?list=RDn4QSYx4wVQg

TUNING: Ricky mostly played this Blue Mark V with the tuning of CFxxFF (x = no string in that slot,) and the album version of the song is slightly sharp, in 446 HZ. He used the string gauges of .058, .056 (not an error on my part, I actually mean an unbalanced .056) and then empty, empty, .018p, .018p. The string gauge part is quoted directly from his guitar tech Keith Bennett (who's also his brother in law) who replied to me on Facebook. (See the replies to comments under this page at the "The Genius of Ricky Wilson" Group.) https://www.facebook.com/share/p/1EgqvVKPBi/

The tuning HZ part was from me, though, having tried playing the song (which did not sound correct in A = 440 HZ) and having made a guitar tab for the song (which is the 4th version of the song tab at UG.) https://tabs.ultimate-guitar.com/tab/the-b-52s/rock-lobster-tabs-2321243

Judging by the 1980 Capitol Theater show (linked below,) Ricky only used this CFxxFF Tuning for 3 songs: Dance This Mess Around, Rock Lobster, and Runnin' Around. (0:37:34 - Runnin' Around, 0:41:27 - Rock Lobster, 0:46:40 - Dance This Mess Around.) https://youtu.be/bVXfkG7q_0s?list=RDbVXfkG7q_0s

Again, on tuning and this Blue Mark V: there are early photos of Ricky playing this same Mark V with different string configurations. I've seen a photo of him playing it in a 5 string configuration from 1977 or early 1978, and then there's a 1978 video in a TV studio where he seems to have all 6 strings while having a surprisingly long haircut. I'm guessing these early examples might be because maybe he only had 2 or 3 guitars to work with until he bought more. This Blue Guitar was also changed back to a 5 string configuration for display on exhibit at the Rock & Roll Hall of Fame, and then it kept a 5 string configuration while on exhibit in Ricky's hometown of Athens, Georgia.

MODEL NAME DETAILS (this is relevant and confusing, so I need to clear this up:) You may note that there was a submission for this same exact guitar as a "Ventures II model," and while there's some truth to it being "the same guitar," here's the story: this Mark V model was first manufactured in August 1965 according to date stamps in the neck pocket of early models (as listed at Max Katzenberger's serial number site,) but it was still using the Ventures II name from a completely different model when it first started, and then Mosrite used the Ventures II name for months. Yes, this is a mess.

The original Ventures II model is what Johnny Ramone mostly used, and it looks very different from a Mark V. Without getting into too much detail about model variations, the original Ventures II was discontinued at or around serial B150, then the Mark V type (named a Ventures II) took over. It didn't get re-named as "the Ventures Mark V model" until roughly at B700 which was in March 1966. The model ended roughly at B1700, with most of the last 100 - 150 or so not having a "Mark V" name on the head. At least some if not most of the last ones after B1687 said "Gospel" on the head, and Kurt Cobain owned one of those.