We have had four wheels from Roy, and although they won't be used on a carrier, just our engine trolley, they look like a good quality job.
We shipped four wheels out to him via a friend in Holland who bought an engine from us, and then the friend bought the replacements over in June.
Price per wheel was Euro 125.
That is a good price as long as the carriage costs are kept within reason.
We have four more wheels to go over soon, we have a second Ruston & Hornsby dynamometer engine set that we bought in February that is going onto a trolley.
Pictures below show the wheels as received, painted and mounted, and the whole engine trolley.
Note that we use 2" axles on the trolley, the bearings are about £7 each (6310 2RS) a lot cheaper than the 'proper' 1-1/4" size bearing.
Peter