Interestingly, having read these posts, I did a little digging on RATOG on the Vulcan.
Vulcan B2's were definitely scaled for RATO, with it being a pair of jettisonable Spectre rocket engines. There is still a sub section devoted to it in the Topic 3 (Spare Parts Schedule) under the heading "Rocket Assisted Take Off Equipment - Removable Items" and was incorporated as Mod 2!
Mod 1 of the Vulcan fleet was "Incorporation Of Rocket Assisted Take Off Gear, Fixed Stores.
Mod 2 was "Incorporation Of Rocket Assisted Take Off Gear, Removable Stores"
Interesting too, is that on the underside of the panels covering the Rapid Start charging points on XH558 (Between jetpipes at rear of engine) there is a warning label, stating "This Panel Is To Be Removed Prior To Fitment Of Rocket Gear", or words thereabouts.
Hmmmmmmmm...
A few more coals for the fire!!
Flipflopman