Good stuff. I think technically you've got a '97 frame (from the shape of the pivot gussets on the rear triangle - have a look at this thread where there is a comparison: http://www.retrobike.co.uk/forum/viewtopic.php?t=169613) when they'd moved to the new style logo, but i'd definitely back date it to '96 or 95' graphics. A Judy SL would look good.
I have a '98 Y-33 frame literally hanging on the wall in the garage waiting for me to do something with. It hasn't got quite as nice lines to it as the earlier frames, but it has a much stronger mount for the shock on the main frame, and longer 'genesis' style geometry which makes it really nice to ride.
BG: The rear was replaced by Trek with a new swingarm so yes, its defiantly 97 onwards, the main frame though is either a 95/96 Y22 as far as I can see from catalogues etc...