In the pursuit of my personal OCD wheel experience...
The only negative was that Mrs Fenlander thought the solids really heavy adding 3.6kg to the pair of legs for her to carry back to the car.... so as I have a secondary use for the solids I've just bought some sandhoppers as well.
£16-50 inc next day post from Ebay... and the bores were the right size to slip over the axle nicely...
2 x Dinghy Launch Trolley Wheels 10" Sand Hopper MP416 - Free Next Day Delivery! | eBay
They are 0.2kg each lighter than the OE pneumatic wheels so no complaints there... and their displacement is minimal so they still have a good negative buoyancy in use of 1.3kg (leg and wheel).
Their diameter is 10" compared to the 11.25" (advertised at 12") of the solids.... so just 0.75" less ground clearance for the outboard skeg.
Please excuse mixed met/imp units.