I have (2x) 8" trailer wheels for sale which I used to fit to our Puck L for storing it in the garage. The holes are filed out slightly to fit the Eriba wheel studs.
Not sure how much it lowered it by but it was enough for it to fit through a standard height garage door. The overall diameter is 400mm if you want to work it out.
They cost around £35 - 40 each new and were only used for a couple of years winter storage.

£30 For the pair
Collection from Coventry