I'm planning on purchasing a Zenith Arms reverse stretched MP5/Z5 pistol and have it SBR, but will need to add the required US made parts to it to make it legal.  I believe that a total of 7 parts are needed to convert an G3/HK91 type of rifle, but with the MP5, I figure 6 parts are needed since there is no flash suppressor on it...  I'm I correct or an I ate up on this??

Anyway, I'm looking to add the following U.S. made parts;

A) U.S. made A2 fixed stock
B) U.S. made 30rd magazine (3 U.S. parts)
C) U.S. made trigger box
D) U.S. made Hammer or sear

A total of U.S. made 6 parts.

I also have another question relating to the U.S. made parts.  Would it be better to change out the hammer or sear?  Basically, looking for something that will not effect the reliability of the firearm.   To date, I've haven't seen a U.S. made trigger that is a true copy of the original HK type of trigger... The only one I've seen was made out of a solid casting and not machined out to "look" like the German version.  If there is a U.S. made copy of the "HK" trigger, then I would most likely swap out the trigger/hammer/sear at the same time.

With at said, I've never seen a U.S. made charging handle that is a true copy of the HK version WITHOUT the very visible "US" engraved/stamped onto the head of the handle.

Basically, I don't mind adding the U.S. made parts, I just don't want any of the "US" markings visible... Yes, I know its a little thing, but its those little things at bother me.  

At this point, I don't want to add a U.S. made handguard since I want to keep the slim handguard for that "early" MP5 look.

Thanks for looking and for any advice!!

You only need 6 parts.

If you do the trigger as well it opens up your options in case you want to swap stocks.  HK parts has PTR parts which are supposed to be top notch.  They have a 5 part trigger pack so if you find a US made slim handguard you can use foreign mags.

(I've been doing a lot of reading on HKPro this past week.)