I'd buy a current production base pin latch assembly (three parts; left side, right side and spring).
I'd inspect the original base pin's "notch". Often a few strokes with a small round file can restore the notch and then
installation of a new "latch" will resolve the issue.
If this very inexpensive fix does not rectify the situation then, by all means, contact Kelye at Belt Mountain for a new base pin.
Actually, a current production base pin will also fit, however the spring loaded plunger in the end, meant to press the transfer bar away from the firing pin, will be eventually damaged and may cause a brief "lock up" of the revolver until the loose parts are removed.
Don't ask how I know these things.....
flatgate