With the water pump in one hand and a £10 second hand alternator from a Fiat in the other, all possible positions were tried to see where they could fit, but they just wouldn't! After a lot of head scratching I found that the shaft running through the water pump was the same diameter & length both sides. Fitting the pulley on the 'other end' sorted it. The pump is marked 'Chrysler' but no idea what model it is from. Any one know? Need to find a suitable radiator next. Most likely one to fit is that of a Fiat Cinquecento. Not sure what they would have fitted in the 1950's?
Awaiting delivery of a new distributor cap and a few small odds and ends............

Couldn't afford a nice  alloy tank so had to opt for this one. Probably made for an industrial application rather than automotive, but at £20 it will do. Won't even have to modify the filler neck! Some reclaimed box section steel came in useful for making the rear frame for the fuel tank and battery tray. It also gives the option for fitting telescopic shock absorbers rather than the A7 friction disc type. (might be one of those jobs sometime in the future that will never actually happen).