Hello all. I'm purchasing a G3 kit right now. My hope is to eventually build it up to be a kick ass little A4 variant clone. I'm considering buying a JLD receiver. I've been reading about how to assemble the beast.  Now, are there any things that are not commonly covered that I should know about this build or rifle? Are there any caveats? The welding of the trunion to the receiver seems a little ambigous to me. I read an assembly article , but I don't understand if I should use the pre-existing trunion, buy a brand new one, or if the receiver even comes with one pre-assembled.  

trunion will be on the barrel I think