Hawg,
I have been following your threads on this forum and the sister site
http://1858remington.com/discuss/index.php?topic=9753.0and find them extremely informative. I see the wood on both your Pietta 1851 and Pietta G&G are the proverbial "plain" straight-grained European walnut which, only IMHO, I find "blah". That is not to denigrate your pistols. I just like better figured wood. I know many folks like to stay with "original" type wood, even going to the extreme of sanding the grip down to simulate ill-fitting wood-to-metal fit as is found on many used original Colts. There are all sorts of genres in this hobby, and I appreciate them all.
After all, this is a replica hobby and one must do as to his/her satisfaction or not.
I purchased a Pietta 1851 Navy round brass TG (date code [CM] 2014) at the end of last year from Cabela's and added a Pietta brass squareback TG to it from Taylor's. I also purchased a nicely figured European hardwood grip from an EBay seller (who parts out Pietta revolvers) as a replacement for the plain-jane original Pietta grip. No fitting needed.
When I purchase my new Pietta G&G from Cabela's in about a week, I will have to discern what the TG and backstrap dimensions are, as I want another nicely figured piece of wood for it, probably from EBay. The problem with Pietta hardwood grips is they have a thin surface stain and any mods to the wood to fit a different configuration must entail removal of wood and a completely different stain/finish.
Well, we'll see.
I will keep you folks posted.
Merry Christmas!
Jim