Since my original posts I've done a few things, nothing major:
1. Replaced dry rotted 165SR15 Michelin XWXs with 195/65-15 Bridgestone RE960AS Pole Positions.
2. Removed original Repa rear lap belts, replaced with Peparts 3-point inertia-reel belts.
3. Replaced door seals.
4. Reglued door cap vinyl.
5. Bought a set of Cocomats, which required that I draw a template for the Sporto-specific driver's side front mat. This is now on file with cocomats.com, if anyone desires a set.