Hi guys, I thought I'd wade in on the tune-o-matic bridge mod topic as this may be of some help to you all. Especially those of you who are new to taking their pride and joy apart or are apprehensive about what it is they may be doing or buying to complete the task.
I did a little research and found that Fender make their own version of the Tune-o-matic called the Adjusto-matic. I picked mine up new from an eBay shop called The STRATosphere for a good price and then fitted the beast.
Looking at the profile of the saddles they are arranged in the same order as the original Mustang unit ie: two high central saddles, either side of these there are two intermediate saddles then either side of these there are two short saddles. This arrangement allows the strings the correct profile for the neck radius... Nice... Problems solved for both string profile and spacing...
The usual rules apply for the bridge posts in the respect of taping the stems to fit the cups. All that remains is to drop the bridge on to the posts...
The neck now needs to be shimmed to slightly alter the neck angle. I found that the Subway loyalty card provides the correct size and shape for this simple task although any store loyalty card will do as long as there are no embossed or raised design features... Cut a strip, 1cm in depth, from the end of the card, remove the neck and place it in the neck pocket hard up against the wall at the pickup end of the pocket... Screw the neck back on tightly (the rear two screws will require extra pressure as they will need to pass through the shim...) As the shim is quite thin there are no detectable gaps between neck and body so no ugliness worries there.
All that remains is to string up, tune up and intonate...
There's a link at the bottom to the place where I got mine...
Hope this helps you out if you are thinking about undertaking this easy mod. Best thing is that it only takes a few minutes to effect and is totally reversible... I use my Adjusto-matic equipped Mustang for all my band's live shows and I love it over the stock unit...
My link