Clembert,
I kind of suspected you had gotten your information from a source like that.
There is no historical record or physical evidence that The Griswold and Gunnison was ever produced of anything other that Bronze, Brass, or various copper based alloys that were the result of smelting scrap materials that were available. Arsenals like G&G were producing pistols to sell to the confederate government and there is no record of them ever even intimating they had the propensity or even plans to produce the pistols out of iron.
The reason that Leech and Rigdon and the other Rigdon enterprises used iron and mild steel was that they also produced cutlery and swords. They had a supply of iron and steel and they had equipment and more experience with working it. There were no chunks of iron available to carve a frame out of, they had to be cast and then hot worked (forged), or were pieces that had been brought in by the blockade runners from mostly England.
Leech and Rigon, Rigdon and Ansley (CH Rigdon), Augusta Machine Works (some actually had octagonal barrels), Dance and a few others had iron frames. The Dance had one because it was a full size "copy" of the U.S. Model 1848, and I told you about the Rigdon connection to iron.
Griswold & Gunnison, Schneider & Glassick, , Columbus Firearm Mfg. and the others who made "copies" of '51s and Manhattan revolvers used a copper alloy for the frames because of availability and the fact the low pressure .36 caliber loads weren't a problem in the smaller caliber.
I use the term "copies" rather loosely because they almost all chose to use an 1848 style barrel assembly rather than the more difficult to manufacture '51 and Manhattan styles. But, I think you know what I mean.
Be careful what you read on some web sites and especially from individuals without any training or credentials. Feel free to question my bona fides if you wish, but don't perpetuate what hasn't been verified by good scholarship and research. Vince (the site you got that from) has put together a nice collection of odds and end "facts." Bu there is very little if any attribution or references cited.
If you want one or more Leech and Rigdon reproductions let me know. As I said earlier there are probably more available with the roll engraving than not. The smooth ones show up, I'll keep my eye out if you wish.
Texas Jack (Cimarron's retail front in Fredericksburg) has at least one in stock, but it may be (most likely) engraved.
http://www.texasjacks.com/BlkPowder/TJ-CA003-LeechRig.htm
if you are interested, then call them and make them look. Don't take their word over the phone, make them pull each one and look at it. They may tell you they are all engraved and then have one (or all) not marked or any variation thereof.
This is what you can do to "defarb" and even remove the engraving on a Uberti, and add engraving.
http://www.cascity.com/forumhall/index.php/topic,21804.msg357484.html#msg357484
And a pairfrom Fingers McGee who also haunts this forum. He has his marked as CH Rigdon arsenal guns:
http://www.cascity.com/forumhall/index.php/topic,37963.msg484685.html#msg484685
Fingers also has Leech and Rigdon reproductions and I believe he even has better pictures on some forums I saw a while back. Maybe he'll come along and post links to them.
Enjoy,
Mako