As mentioned phoned Vans and they were not help on this.
I did however, the same as you suggested. I took the rollbar off, and began riveting the 705 G L& R AFTER! the rear side skins were riveted on.
As you mentioned, you MUST allow for a pocket in the side of the 705G in order for the shop head of the side skin rivets to find room. This was essential and to my account I could not find this in the 10 year old version of manual.
The unit (Rollbar and angle iron attachments ) were reinstalled and all is well again. Building on as they say!
Thanks for your reply.
=VAF=2018 Donation - and a bit extra for great work!
Empennage RV 7 - Tipper
Fuse nearing completion, Canopy complete
AME reviewed and repaired O-320-Lyc installed