Hi Peter Bowman, I have an AC engined Aceca and I obtained an overhaul kit and a conversion to electronic kit from Burlen Fuel Systems who look after SU, Amal, & Zenith.
Email info@burlen.co.uk web
www.burlen.co.uk I dont know if my pump is original but ran well since 1976. You must stipulate 'Suction' and 'Positive Earth'.
They have new pumps as well as parts.
After overhauling my reserve pump I fitted it alongside the original and it tested out ok but failed after 20 minutes running. I re-tested and ok but failed again after 20 minutes. In each case I was able to swop over to the original which works well. Burlen suggested that some old solenoids fail when warm, presumably an insulation breakdowm. I dont think the fault lies with the conversion kit.
Hope this helps
Peter Hoskin, Canberra, Australia