Classic Army Functioning Bolt Catch

[warbird]

I have a newer ish(2-3 y.o.) Classic Army M15A4 that had a working bolt catch, I somehow lost track of it a while back. Would anyone know where I could find the original part?

P.S. : The bolt catch doesn't engane when your mag is empty, but you can manually engage it by pulling the bolt back, pressing the catch and finally releasing the bolt.

Thanks for any info!