Fed my friend's now-slightly-less-shiny Kalkhoff some overdue air and chain lube. The
foot pump we bought form Decalthlon was declared a success - it managed 70PSI or so without too much drama, and I was quite impressed by the ease-of-use of the chuck (in Schrader mode). It may yet turn out to be made of cheese, but it's better than cheap nasty compressors or not being able to use a hand pump.
Chain lubrication was complicated by the cranks freewheeling at the motor, so the only way to turn the chain was to lift the rear wheel and turn in the forward direction, or just pull the chain backwards by hand. I opted for the latter, because heavy ebike. I regretted this as I managed to derail the chain at the chainring end, where it's thoroughly enclosed by a case. Eventually we worked out that by removing the battery, and with assistance to lift the wheel, I could get a couple of fingers in behind the case to re-rail the chain on the drive side of the sprocket while turning the cranks, and didn't have to dismantle anything.
The chain's still a little on the slack side of ideal (but I now realise this likely doesn't matter when it freewheels at both ends), and I've only looked up how to adjust for pad wear on HS11s in retrospect, but I did sort out the marginally rubbing mudguard and it should be fine until next time I'm in the vicinity.
Also fixed a rear light bracket onto the mesh of the rack-top basket, which it turns out was just big enough to squeeze an M5 bolt through with a little ultra-violence.