Thanks for that! Will keep up with that thread.
I have had limited time working on mine so it is still in progress. I had something of a shock when fitting the chainset and front derailleur: I have got used to a Shimano 105 triple and a 12-27 cassette which gives nice close gear changes and a low gear for the odd 20% hill (one or two around here). I had an unused FSA triple (52 39 30) so I fitted that and promptly found that the mech hit the frame in a position that would not get near the inner ring. I eventually found that (probably) this chainset needed spacers on the BB cups. I fitted 5mm worth of spacers which has brought the inner ring into roughly the right position but will have to wait until I have the cables and chain fitted before I know whether it works or not.
I would be disappointed to have to buy a new chainset and cassette if the triple doesn't work. The Schlitter website does not imply any restrictions like this. I suppose most of the US buyers have bought complete bikes with doubles but there is one picture on that thread which looks like a triple chainset. Will follow that up if my problem persists.
Alf