MaxP,
That is a BEE-YOU-ti-ful Vaquero, Pard! Congratulations.
Please let us know how she does in the field.
Apples, 10 or 15 years ago a lot of guys were doing conversions and lots of conversion parts were available through Brownells. I never messed with them because I had bought mine back during the day. I can tell you this though, the Bisley grip moves a whole bunch stuff "around" but not so much that the conversions couldn't be effected by most anyone with a decent education in mechanics.
Colt came up first with the "Bisley configuration" - a highly modified Single Action Army just before the 20th Century. . It was manufactured until 1915 IIRC.
And it was named for the location of The British National Rifle Association Matches regularly held in Bisley, England. BTW: that's pronounced "biz-lee" not "bees-lee".
In the mid 20th Century Elmer Keith played with a modified Bisley and ended up with something close to what Bill Ruger tweaked and produced as the Ruger Bisley.
The lowered Bisley hammer is part of the configuration and drops the top of the hammer below the top of the frame thus allowing the shooter to more easily re-cock the piece with less disruption to the rest of the hand-hold.
The straight drop on the grip turned out to be the cats whiskers for shooting late 20th Century heavy loads, as it all but eliminated the upward "roll" of the plow handle and channeled the recoil straight back into the web of the hand. The straight drop grip also makes them natural "pointers" for me.
OTOH: the configuration is downright "plum-ugly" but the wallflower effect is mellowed and softened by the end performance of the piece.
If I could have only one handgun, it'd be a Ruger Bisley. It's built like an anvil, points like my strong side index finger, and mitigates recoil like no other handgun I've ever fired in my 73 years.
But this is just one old man's opinion. I know a lot of guys who flat out detest them.