Thanks to all for the advice and encouragements,
At the moment I am slowly but happily grinding up hills (we have big one's round here - lot's of them!) and happily flying down them and along the flat. My face aches a bit from grinning.
The tyres on the trike are "Schwalbe Marathon Racers". Dave Mccraw says of them
More rugged than Schwalbe’s Kojak slick, but also built to a higher standard, this should be a very interesting tyre if you’re looking for a capable all-rounder.. I have no idea what tyre is best for my aims but I'm not going to be racing anywhere anytime soon - I'm trying to rebuild aerobic fitness and muscle that has atrophied over ten years, so even if the tyre makes it harder work that is actually not a "bad" thing.
For now these tyres seem fine. I will be using the machine on the road, to go shopping , on cycle tracks (some paved some not), on green lanes, unsurfaced roads and off-road - often all in one trip so I wonder if there is an "ideal" tyre for such mutipurpose all terrain use. I do need some protection from easy punctures and I don't want to be constantly swapping rubber or stopping to fix a flat.
Also I have to actually pay off the bike (Thanks interest free credit card!) so being a bit careful about spending more money for the time being.
Quint - yes I was looking at the Shimano PDP M324 SPD that ICE sell - as I do a combination of round town and plan for longer trips. Not familiar with Crank Bros - will look into it.
Tigerbiten - thanks for the heads up on the potential to swap the inner ring for a 22 - so far I am not having any trouble with the gearing, despite the steep hill-climbs around here (and that's not even getting far out of town).
Yesterday I did a total of 5 mile round trip with 350ft total vertical climbing in that distance - legs were very wobbly at the end. It's going to be a journey from where I am now to anything resembling "being fit".
Kindly,
Matthew