My cheap digital tyre pressure monitor has given up the ghost (I merely had a bicycle schrader valve attached to a plastic tube which slotted into the valve).
Having done some searching on the web for a replacement, I noticed that many LCD tyre pressure gauges only operate above 5psi but I want to measure 1-3.5 psi (since the Futura performance badly suffers from being under inflated).
Various online chandlers do sell analogue air pressure gauges, but the postage costs seemed unreasonable (typically £5-7), however for the princely sum of £7 (delivered) - I have sourced a replacement gauge which doesn't require a battery :
I will of course have to connect it to a short length of tube which has a nail inserted about 3/8" from the bottom (to open the valve) - but I already have that from the old arrangement.
Hope this is useful to someone !