Well I’m pleased to report that it’s now built- albeit with a few temporary fixes, that gross rear saddle for example, and I’ve had to reuse the old worn out chainrings for now in the absence of suitable others- and I’ve taken it for a test ride. A few teething problems related to the gears but generally all good. Feels very smooth and responsive. My dad informs me that the last time it was used was 1980 when he and grandpa took it up to the Wayfarer memorial in the Berwyns. Grandpa had a stroke six months later and died in October 1981. Dad - himself now 74- is coming to stay in a week or so so I shall make sure we take it out for a quick spin.
Guess I can add it to the ‘tandems of the forum’ thread now!