Russ, thanks for doing a build thread. It's nice seeing the changes and enhancements HM has made on the HM 2xxx series cars.
I couldn't tell from your photo of the IRS and I don't know if the manual now covers it, but be sure
both bolts attaching the lower control arms to the frame have the heads facing
inward with the nuts outside. If the rear bolts have the nut on the inside, the gas tank will prevent you from removing the bolt to align the rear.
You don't need to ask me how I know
Good luck, have fun and keep the posts coming
Matt