I only have the earlier Nikkormat FTn. Can't comment on the meter issue as mine runs perfectly off SR44 batteries now I've fitted the conversion piece that allows it after the mercury 625 batteries became unobtainable. (Well I still have two I got in China, but I've made the conversion anyway.)
I recently replaced all the door seals and the mirror damping pad in both my bodies with the precut kits obtainable from John Goodman. The only required extra was to get some Surgical spirit and a packet of cotton buds. Comes with full illustrated instructions and covers the FT3. John used to sell off EBay as "Interslice" but I think he doesn't do that any more. If your camera needs seals, contact Jon at 'JGood21967@aol.com'. He's based in Dallas, texas, but his service (and product) is very good.