As far as the model it's a Brazilian contract 1917. So the serial number is on the back of the bottom. It doesn't say US Army so there isn't enough room I don't think to round the butt off to make it a official round butt. Other wise I'd have to make custom grips.
I may just cut it down to the ejector lug and try it like that for awhile and see how I like it. Then I can look for another barrel in the mean time and see what happens from there before I cut it extremely short.
Normally the serial # on a pre war model is centered w/o a lanyard swivel and the 1917 US Army are fairly simple because of the serial # location. But since the Brazilians were made with swivels, the # is moved to the rear. So round butting is not that simple.
To rd butt a 1917 US Army or pre war N frame w/o lanyard swivel:
The rear corner of the butt is hollow so it can't just be ground off, the backstrap must be cut loose from the butt, bending the backstrap forward 5/16", and welding it back together with the butt. Cut off the excess butt length and grind the heel off 1/8" to round it to the rd grip. Then grind off 1/4" from the front toe, round it, and grind the taper up the fore strap almost its full height to match the rd grip. Re-countersink the tension screw hole for the screw head and cut the screw length to fit.
To rd butt to fit a standard N frame rd butt grip and retain the serial # and lanyard ring on a Brazilian or commercial model:
Instead of doing the above, don't cut the backstrap at the heel. Cut the butt/backstrap loose from the grip frame by making a cut thru the toe horizontally just above the lanyard retaining pin and leave the backstrap attached to the butt. Now bend the back strap and butt forward 5/16".
To re-attach the butt/backstrap to the grip frame and maintain the grip's original length, make a "fill" weld in the cut. Grind off the heel corner of the backstrap 1/8" to round it to match rd butt grips mounted on the locating dowel. Cut off the excess 5/16" butt length at the toe, and rd the toe to match the rd butt grip. Grind off the taper up the forestrap to match the grip. Re-countersink the tension screw hole for the screw head and cut the screw length to fit.
The full serial # and lanyard swivel hole has been retained. The swivel hole will be right under the bottom of the mainspring. Slightly deepen the swivel hole thru the fill weld and re-install the swivel. The original position of the grip dowel and mainspring retention groove are undisturbed. Polish all ground surfaces and your done! No more work than to do a normal rd butt conversion.
Hope that helps and you can follow it,
. Really enjoy that guy.
