SDA your description of the modded 100E, brought back loads of memories, and I planned to do the same with the very same components, but never had the money in those days,
I also did the sleeping in the car bit at LM, and recall sitting in one of the restaurants on the Mulsane Straight, about mid morning on the Sunday, and thinking the conversation had dried up a bit only to look up a see my 3 compatriots all peacefully asleep as the cars blasted by at well over 200mph.
You're right LM in a motorhome is a bit easier, but we're a lot older now and need our creature comforts.
Andrew