FYI: 2 types of Vaquero's,,, Vaquero & New Vaquero,,, both are New Model guns.
Now with that said,,,
Some confusion happens when a Vaquero is referred to as
Old Model, in an effort to convey
Original, or Full Size, or Two Digit SN# Prefix.
Say; New Vaquero, because it states that in the side of the gun, That is a "Medium" size frame,,, with a Three Digit SN# Prefix.
The 2/3 Digit SN# Prefix designation does have an exception, when a 44 Magnum is involved,,, another day & discussion.
Robb Barnes suggestion of John Powers is an excellent option,,, IMO.
contender's post is just trying to let you know you need a
New Model Super Blackhawk Grip Frame, if your wanting the square back trigger guard.
Another option is Hunter grip frame, same
Super Size with a Round Trigger guard.
Most don't care for the
knuckle bustin square back in larger calibers and opt for the Hunter option.
fwiw; Before the Hunter GF came available, some would have the Square Back reformed to round.
I didn't care for the smaller XR3 grip frame that came on the 50th Anniversary of the 44 Mag Flattop,
I changed it out for a
Brass Hunter GF, now it is a pleasure to shoot. At the same time changed out the Hammer to a Super.
I like where your going with making your gun yours…
and I like the Look & Size of the Square Back GF (Most commonly referred as
Dragoon.
Brass Dragoon on my 30 carbine