Dreamlander...
The safest thing to do is send Gordon your old pins and let him match them. I have ordered from Gordon 3 times... the first two orders (4 sets of bridge pins and some end pins/strap buttons), I sent the pins to him, since the sizes differed from set to set. All were pretty standard fare for him (bone with ab or tortoise inlay), and it was only ~a week from the time I sent my pins express mail until I got the new ones back. I stuck some temporary pins in my guitars (I had some Tusq pins I no longer use) while I awaited the new pins.
The last order took a little longer, since I wanted black horn with gold pearl dots. Gordon had to order the dots from StewMac...so it took a little more than 2 weeks. However, in this case I measured the pins, and they were pretty standard sized (0.215 x 5 degree taper)... so I saved the $4.05 postage it would have cost to send them.
You might go to your local shop and get a cheap set of plastic pins to put in so you can play while you send the originals out to be copied (doesn't matter if the temps are a little loose, as long as they stay in). I highly recommend Gordon's work... and he and Betty have been a pleasure to deal with. I think his contact info is posted earlier in this thread.
Dave