I have a set of wheels similar to the Danard on my rubadub.
They are cruder and much cheaper, the fixed part is a SS chanel and the struts for the wheels swing about a pin through both the channel and strut. Another pin is used at either the top or bottom of the channel to hold the strut either up or down. The pins are secured by small R clips.
You need to be careful to mount the wheels far enough apart for the outboard
to swing. I've learn the hard way.
Like every thing that we buy in England
that isn't made in Germany
they were made in China
and from memory, I got them off the guy I bought the dinghy
off (also made in China)