For the past 6 months or so I've been on the look out for one but it's a discontinued part by Winchester and I've also tried many parts suppliers in the US too with no luck.
I've spoken to 2 gunsmiths and an engineer, each said that they could weld on and shape a stop (at a pretty high cost), but whether it'll hold up is another matter.
I was thinking of selling it as is but thought I may be able to get more if it's deactivated?

Also have a regular size lever loop.
The broken piece.

How it should be:

What is the cost of having a firearm deactivated and a certificate issued.
What would you do?