I bought it in 1970, played occasionally but hasn't been used for the past 15 years.
and the floating bridge adds to the problem to stay in tune. has any sort of modification been done on this that you know of ?I really like M65's but the tuners are the worst! I can't believe Guild put such crummy tuners on this guitar. I get it was a student grade guitar but the difference of a couple $ for better tuners really reduced this guitars potential!
I was curious about your bridge mod so I looked at the wood bridge with the adjuster wheels and found a couple of washers that were about the same thickness as the wheels. The washers lay flush over the threaded posts instead of the wheels and with the wood bridge on the washers this lowered the strings a bit. About the tailpiece harp, did you notice that with the angled string mount rail on the harp, that the G,B, E strings are pulled downward in each slot and are not centered causing the E string to be closer to the edge of the neck.I had and have a number of M65's. The best playing of the bunch had Grover tuners installed and a posted adjustomatic along with removing the harp and putting a hard stop. It also feels like blocks of wood were installed under the bridge. I didn't make the mod but bought it that way and it has a pair of Gibson HB pickups. There are others with additional mods like the one with the Franz neck pup and added bridge HB and varitone multipole tone knob. Main item is the changed tuners.
I just acquired a few sets of Grovers with the intention of replacing the tuners on more stock M65's. Another mod was replacing the little floating feet with a Bigsby bridge base and remove the height adjustment wheels to lower the action.
so I got a metal bridge with the metal saddles that fits onto the original threaded posts that held the wooden bridge. It is a perfect height with much lower action due to a very straight neck with no buzzes. I put a small piece of sheet silicone under the posts that grip the posts to the body and I'm surprised it works so well.There is a tendency for guitars with floating bridges to skew the strings towards the lowE side. I don't think that is unique to Guild. That may explain why some people install very fine sandpaper dabs under the bridge base. That increased friction between the bridge base and polished top surface of the guitar is improved and allows you to position the bridge to better center the strings.
On one NS CE100 that I acquired from a guy in Nashville ...he must have becomes annoyed with the issue you mentioned and drilled two holes through the bridge base and screwed the bridge into place. I'm actually ok with his mod but would have preferred a little more effort to center the screws so the mod looked more professional. LOL!
the silicone "sheet" is actually a card of silicone bumpers for cabinet doors etc. that is the flat thin space between the bumpers which I cut to the right size to place under the threaded post feet. But I did find a silicone sheeting in various thicknesses from ebay that I ordered and may be a more exact thinness less than 1 mm.That's the ticket! Glad to know your technique! That sounds like the best modification I've seen yet.
I'm curious...where did you get thin "sheet" silicone rubber?
As a subtle point the metal bridge will brighten the guitar tone. I have taken rosewood bridges used a bench grinder/sander to reduce the height and step around the post to fit a wood bridge under the strings. Just a thought if wanted to soften the tone a bit.