I saw the exhibit on Tuesday and it was excellent.
It included interesting history from the matchlock period through the flintlock. There were numerous wheellock guns on display that were exquisitely crafted. The wheellock was an expensive gun to make, hence only the very rich could afford them. Most all the wheellocks being displayed were adorned with all sorts of inlays, both in the stock and on the metal parts. It often required several craftsman to make one gun. For instance, a cabinet maker would work the stock while another craftsman would do the inlays in the barrel while the gunsmith would make the metal parts and perform the final fit-up and assembly. Interestingly, I noticed that the position of the touch-hole varied quite a bit from gun to gun. Also, some of the touch holes appeared huge, (~3/32") perhaps this was a design intent or perhaps the hole was worn out.
Jason