Still on my Mionlta HiMatic 7s mission.
Opened the lens assembly of one that was having intermittent shutter freezes and a bad lens wobble. Found a mounting screw rolling about in the lens barrel (not in a space that could have hit glass or the helicoid, but yeah, there's your wobble). Cleaned the shutter & iris with 90% iso (all I had handy... I like coleman fuel for this but the stuff is so explosive). Worked like a charm though, the usual "pop" after a bit of a bath as the shutter snaps closed again (amazing how pleasing that is!). Iris now smooth to boot. Put it all back together and the lens has very minimal play. The last bit is likely the big shutter retaining ring at the rear... but that is huge, gory surgery to get to.
My $15 eBay lens spanner worked like a champ, very pleased with it.
Funny, there are dozens of "loose lens" and stuck shutter posts on google for this camera, with dozens of people saying it's one of the toughest nightmare lenses to work on. One retaining ring and three screws? I found it easy and all the parts make sense for reassembly.