I believe the Seatiger uses similar
gypsy labeling as my Seawolf 500. I'll have to dig out my manual and notes on the
boat but if I
recall the only important thing is the first number on the
gypsy, in your case the #6. The other numbers are SL version revisions, casting numbers, etc.
Also be aware that the original SL
manuals were HUGELY optimistic about what chain would fit in what gypsy. My manual shows 10-15 different chain sizes for my gypsy and I can guarantee from experience they don't all
work.
You can also check with John at SL Spares in
Scotland. He used to
work for SL in the windlass end of things and bought out all the rights and old
parts for the old windlasses. If you need any
parts that aren't standard (like bearings and such) he's the go to guy.