I tend to buy mine from US Barrel Shroud, although they're also just 80%/not full length, just a repair section missing the front trunnion area. They also have a blocking bar already spot welded in place, but they only run about $80.
If bent, but empty, they're a receiver according to the ATF. You can't buy one without markings unless it's flat, or short of full length.
Quoted:
"I" want to built a "replicant/fake" copy of a FN licensed Uzi and have it engraved with a serial number and any FN type markings on the left-side of the receiver AND then find somebody to finish the receiver AND engrave their manufacturing/FFL Class I builder's information on the right-side of the receiver to make it 100% legal... I have a local gunsmith with a Class I license that I plan on using to do all the welding and finishing of this receiver and to complete the build.
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Do you mean that the gunsmith has an 07FFL? He needs one, to manufacture a firearm for you.