You're really moving along with this thing! Appreciate the pictures; hope you keep them coming.
Those 2x4s and blocks are scary.
Are you going to put gussets where you weld the frame back together? There are some nice photos of "fish plates" in firstname.lastname@example.org's Journal
on here. I'm not suggesting that the bug is going to put the same kinds of strains on that frame joint as a front clip for a pickup, but those plates don't add much weight for the added strength.