Horita BSG-50, that’s right, BSG-50. 1800’s need sync like bears need honey.
How far off is your timecode? Maybe the settings are off on your deck and your set up for freerun instead of regen timecode? Are you doing an assemble edit? Did you run a little heads with heads/tails before and after the time you want your timecode to start? YOu don’t have to black & code the whole tape, just the beginning. If you want your timecode to start at 1:00:00:00 then black and code starting at 59:40:00, run the tape past the 1 hour mark, then tell FCP to assemble at the one hour make. You should also calculate your frame offset for dead nuts accurate timecode.