Slight hijack -- at coffee this morning a local (crafty) TR3 owner showed me a set of 'soft' side curtains he made.
They secure with a loop to the tenax at the top corner of the windscreen and to the LTDs along the bottom edge, then there are a pair of velcro straps that attach around hood sticks.
They have a soft window that unzips & lowers. The pair roll up into a soft bag that looked to be about 5" x 16".
In case you're trying to visualize the process, you have to undo the bottom LTDs to be able to open the door.
He said they only leak a bit in a heavy rain... but then most sidecurtains do.
Packing the original side curtains for a long road trip takes so much valuable/limited space that these seem like a very attractive alternative.
He's offered to make a set for me so when I have them I'll post again with pics.