Gave him a boost charge yesterday, then put the dehumidifier in him overnight. Cover off, dehumidifier off and took him for a 2 hour 55 mile waft around north west Cheshire today - first time out in 10 weeks or so since we moved.
One false start - probably fuel vaporisation / air in system, started fine second attempt and worked faultlessly the whole run of mixed driving. Saw another P38 (green) that was leaving Delamare station as we drove past.
Checked when we got home, the hot starting issue is still there, although he was starting poorly and running rough for a minute or 2 before it cleared, unlike before we moved house where he was refusing to hot start.
No fault codes on the Nano, so guessing it is a fuel pressure issue. Fingers crossed it is some sort of vacuum pipe leak / issue like the non-working cruise control seems to be, rather than the £100+ for the fuel pressure control unit....