First let me state that I'm not even a gun smith's proverbial and can't give any sort of expert advice. I did find an article which may be of some help to you.
https://www.enfield-rifles.com/charger-bridge-replacement_topic7930_page1.html

You would need to source a charger bridge from somewhere, either a mil-surp parts dealer or maybe a dealer with a junked receiver. Be aware that the holes in the replacement charger bridge may not exactly match the holes in your receiver. I note from your photos that on your receiver the rivet holes appear to have been filled with screws this might make it easier than if you had to rivet. If you need to rivet, be very careful as it would be easy to damage the receiver wall.

Good luck and let us know how it works out.