Just to answer whether a Gotoh will fit, yes it will. I swapped the OFR on my ESP M-II to the Gotoh (the guitar was used and the OFR was corroded throughout). Due to the routing on my guitar and the size of the posts that come with the Gotoh bridge, I left the OFR posts to mount the Gotoh against. The 1000 series Floyd has a great feel, so does the OFR, but the Gotoh feels even better under my palm. Most importantly though, it is a solid unit.
Cole
I guess you didn't try the Gotoh locking nut for a replacement. So the OFR posts work perfectly fine with the Gotoh bridge? I had a chance to check the original Gotoh posts and compare with Floyd ones, and the design of the post inserts was fairly different too, I mean the upper curvature that works with the bridge knife. How would you compare the 1000 and the OFR, no major difference in feel, sustain, tone etc?
Okay an update: I couldn't get the luthier to fix my problem yet but I tried the chapstick idea and it works. I guess I just had to look up what 'chapstick' means earlier to see that the method suggested was not anything complex or esoteric at all - no joking. Yes it seems the trem will work as long as I got a chapstick ready to apply when needed. Anybody thinks nevertheless that an upgrade in the trem from FR1000 will make one a happier tremmer? thank you...

Well a luthier thinks the knife edges and posts are worn... I am not making the whole idea up
Talking about Russian reliability, etc.. there is a elder gentleman from Russia called Aleksandar Chromov : https://www.youtube.com/watch?v=-yirZut2TCY who makes IMHO the smartest trem setter design which might be the answer to your problems. Its about 15 EUR IIRC. I have one and regret not buying a second one. The guitar can do dives and pull ups, NO mods to the guitar are needed, but still one cannot have full floating trem (not big deal if you ask me).True... we did file it, it still doesn't get back to tune after a pull-up... some chipping on the posts and knife, I think I know it is the knife edge and posts because it is the same syndrome with my strat, I had to deck it so now it goes only one way and works alright. I tried multiple set up strategies with this one, nothing expertly, but still I gave it some hours... I have just read yesterday that the bridge need not be parallel to the body with Floyds, maybe should try different angles, but then need to try some angles with the neck too I guess... anyhow tomorrow someone else will look at it. By the way I located a Schaller Lockmeister I can actually get - there is a problem of transfer of payments we are having here - where I can choose block and nut size, unlike Thomann - disappointing - and for a very reasonable price IMO, still for a bit more money than Gotoh. It is a company from Russia on Reverb, 'Rockstargear'. Honestly a Russian company wouldn't look trustworthy initially but it appears to be doing good work. Nothing against Russians, I might not trust a Turkish company - that is me - if I were a buyer from Russia, it is a world-situation thing. If anybody knows them let me know.