the new mfg win 1886 has a tang safety but no half cock the browning had a half cock but no safety does anybody know if you can replace the win hammer with a browning so that you have a half cock

No; the new ones have rebounding hammers; totally different system. You might be able to replace the hammer, trigger, and spring, but I am not sure. Probably not; Miroku designed it only to please the US lawyers.
Browning, Winchester, Miroku; all same.
Just weld up the safety slot on the tang and live with it.
In fact, I took one apart last week; what a mess. Barrel was not even torqued in; they glued it in.

Turnbull returns them to original design. I am not shure if they alter the parts that come in them and delete the safety and cut a 1/2 cock or replace the system with old style parts.