Maybe it's not the key. A little touch of lube on that seat latch bar makes a world of difference in how smoothly it latches/unlatches. (Murphy's Law says it will start binding right after you get a new key!!)

If it IS the key and you can figure out how the seat latch tumbler comes off.........90 miles is a good afternoon ride. I'll bet that same locksmith could fix it right up for little or nothing.

I use white lithium grease on mine. Put a little on your finger and rub it on the pin. My latch was sticky when the bike was new with new factory keys. Lithium grease took care of it.

This reply is late in the game, but it might benefit some people that are still looking to get a spare key made.

My GZ250 came with a spare key key made by ilco with the markings X241 and SUZ18.

ETA: Here's a picture of the key head:

http://i78.photobucket.com/albums/j8...ke/ilcokey.jpg

I went to a locksmith that KNOWS how to do bike keys. He advertised it in his ad. Took him a tank once and he made the key in about 5 mins. Smooth turning. Try someone who knows what they are doing.