For those interested, there are 2 old Griswold & Gunnisons on Gunbroker.com.
621873030 and 625370117. Not sure this last one has a brass frame. If steel, it's a Leech & Rigdon.
Thanks for the post, RC.
Insofar as the first one http://www.gunbroker.com/item/621873030
I have problems with it. There are no proofs or manufacturer date on the frame and the 3 frame screws as well as the forward trigger guard screw are not original to the pistol (flat heads, not blued, wrong screw slots). It appears to me that the frame has been "sanded" to remove those "terrible" Italian marks. It may be a defarbed pistol, but a poor one at that. With 11 bids at $121 a few people are interested.
The second one http://www.gunbroker.com/item/625370117
looks like a good one for replica collectors. It is a Navy Arms 1851 Navy brasser made before any repro collectors were interested in G&G's. To me, everything on this pistol looks good, even the wedge screw (which most newbies think has to be removed for some reason).
If one is a collector of repro 1851 Navy type pistols, I would watch and maybe bid on this one. The market for the old repros is steadily gaining in price, and IMO, rightly so.
It all depends upon the direction you want to take.