It's not unusual to see Colt and S&W "target" stocks that have been modified.
There was a Colt 357 for sale on one of the auction sites recently that had the first model fully checkered grips that somebody had modified with a later style "thumb rest" cutout.
Actually those ARE "Python" stocks, in a way.
At least they fit Colt revolvers.
Those stocks with the S&W-like checkering panels were made, "I think" by Jay Scott, a company once owned by Colt, and who made some grips for Colt.
Colt used Jay Scott to make low-end, mostly hardwood grips for some "budget" Colt guns.
I "think" the orange colored hardwood "J" frame Mark III grips were made by Jay Scott.
These things have been sold without the Colt medallions for as little as $9.95 by some catalog companies.
Colt apparently did sell some as after-market grips, thus the Colt medallions. I've seen a few pairs still in Colt marked bubble wrap packages.
However, whatever the facts, these were NEVER true "factory" grips. They were never assembled to Colt guns at the factory.
Colt's sole involvement was they MAY have once owned that company, and sold a few of them as after market items.
I consider these to be "legal" rip-offs. They are rarely advertised as "factory grips"
but usually state something like "Python grips" or "factory type" grips. Just enough to avoid fraud charges.
The ones with the medallion were likely sold by Colt as a fill in when they were in bankruptcy distress , the non-medallioned ones were just generic fits-the-Python after market.
I see these occasionally on Pythons sold as "Factory original".