Purchasing of firearm parts without a PAL?

[-=ArchAngel=-]

Hello!
I was wondering about the legality of the purchase of firearms parts without a PAL. What parts are and arent allowed to be purchased without a PAL? More specifically, the lever from a marlin (or maybe a winchester) lever action rifle.
If you must know what it would be used for, it would be for a lever action paintball marker project. i was thinking of converting an old cheapo paintball marker's pump action into lever action. While i could fabricate a lever myself, modding a preexisting one would be much easier and prettier.
If these types of topics are not allowed, i am sorry. If not, any useful input would be greatly appreciated.
Thank you

 

[dHb]

You only need a PAL to buy a receiver.

 

[m.taylor]

You probably already know this, but mcarterbrown.com is a good source for parts like that and knowledge.

 

[destructo_d]

What an interesting project.... do you have any kind of machining skills?

I am sure I will get some hate for this, but I would like to see the finished project....

Could even do a "theme" wild west tournament if there was enough interest