Two questions for you, OP:
1) What the fuck is an "A-10 style receiver"? and
2) Did you do any research into Spider Firearms? I've been into this shit for a long time now, going on nine years, and have not once heard of Spider Firearms. I read this kind of shit and it just boggles my mind. I get it, particularly with regards to custom builds, shit happens, tooling breaks, vendors run out of necessary items, etc, etc, etc...but your guy (Spiderman) went from, "it'll ship at the end of November" to "where the fuck is my rifle" a half a year later, that has got to be aggravating as all hell man.
I can appreciate the hell out of many of these QUALITY gun builders telling folks their builds will take 8-12 months, at least they're shooting folks straight.
When JP built my LRP, they quoted me 12-16 weeks. I had it in 13 weeks. That's some outstanding customer service.
If I were in your shoes, I'd just be damn certain everyone else on planet earth knows who Spiderman Firearms is and that maybe buyers should beware.
I hope it works out for you.