Howdy,
I recently put one of these things in my 51 uberti colt navy.
I got part from Dixie and one from VTI , VTI part was about $8.00 more. I wound up using Dixie part which seems a but stronger. I never touched spring just worked on hand. VTI part was genuine Uberti I was told. Both were about 1/4 inch oversize and had to be shaped on sides . Go slow and keep checking fit.Here is my review to Dixie on thier part. It is still working and like I said it apears to be a bit stronger in the spring area. Hopefully you still have broken hand to measure with.
Quincy1
--------------------DIXIE POST on PART #MP1813----------------------------------------------------------
"Well this was my 1st experience replacing one of these. I had to get out the dremel tool after a few days with a file. My original Uberti hand had a broken spring only so I had some idea how long hand had to be. Be prepared to install and remove this thing a number of times, although I discovered I did not have to install the grip frame each time I tested the fit. I took about a ¼ inch off the length and than kind of shaped it on the edge (front and back). I knew I was getting close when I installed it with trigger, bolt, hammer and cylinder with barrel and it worked ok but would not let the hammer back to full cock. That’s when I shaped it a little like the original and Walla it worked."