Bought this before I knew enough about the platform. This won't fit my PTR. 

This allows you to use an AR15 fire control group in your MP5. You can use your favorite AR15 drop-in or trigger and hammer set for a much better shooting experience.

https://leesporting.com/products/ls5-stg-swap-trigger-group-k-push-pin

Also available - DNT D2 super safety, cut milspec trigger, milspec hammer, Nylon-CF slip trip - ask for more details. 

Cash or venmo. Considering trades for threaded 9mm pistols, AR15 complete or parts, reloading components, other 2a related items.