Gentlemen,
Sorry for not responding earlier, but I've been snowed under with that 4-letter word "work", spending many evenings and weekends there lately. Playtime was suspended while project deadlines loomed!
The Vsonics are sounding great at the moment, though I may have overdamped the lower chamber by completely lining it in 1mm felt. The bass is certainly there, but it's not as visceral as before. When I'm sure the drivers are mechanically run in, I'll remove the felt piece by piece until it's right.
Things haven't been helped by an "upgrade" I performed a few weeks ago, replacing Opamps in my DAC with the latest and greatest. The first one I did made a good improvement, but the second resulted in sibilance. Needless to say, I couldn't re-install the old one again, as the leads were snipped to get it out. I'm just waiting for a new (old) one to arrive, then normal service can be resumed.
Ginger, that Elan must have been one-of-a-kind, I don't think I've ever seen one where everything works, even newly restored they have their quirks. It's good to know "The Old Man" as Colin was known actually saw one Elan where the electrics worked properly!
Lotus did a fantastic job on suspension, brakes, steering, roadholding, etc, but electrics were the weak point, as with many Fibreglass cars. The earthing is definitely the key. In addition to using the Chassis as earth, connecting at points that were prone to rust, Lotus used loads of "Bullet" connectors in the earth leads which weren't sealed against the elements, with the resulting "Bad Earth" problems becoming all too familiar in the soggy climate here.
I intend to do something like you did, by using a 15-fuse box and proper sealed earth connections throughout the loom. Given your experience, I think I'll also run a length of thick cable from engine bay to the rear electrics rather than relying on the Chassis earthing.
Cheers,
Ron.