I'm certain the SG mold is exactly the same as the siege mold. There looks to be is a tiny bit more gap for the earthrise mold, but I'd think it so small as to be negligible. Any time. Like I said, I'm just glad it got released. The little tweaks along the way are just part of customizing.
Just a heads up. The G1 and g2 Megatron heads are available to be ordered (printed and painted). The prices for either are: Megatron (3 faces): USD$13.5, CAD$17.41, GBP11.20 Please see the Kuphead thread for more details. The Kuphead thread.
That is amazing quality! You should do the g1 Megatron black helmet head. I believe it was seen in g1 toy commercial.
Hey Madness, don't suppose you have plans for a MP/Cartoon accurate head for the various Optimus Primes?
No, no plans for Prime. I'd imagine there are plenty of good options around already, though. Awesome man. Looks fantastic!