Hi,
I recently bought a Van de Stadt MB21 trailer sailer and was keen to know if any others exist out there. Being a 40 year old boat, they don't come with an instruction manual!
I want to do a few mods, but would love to hear what other people have done. Also keen to know how seaworthy they are. That is, how far have you pushed it? What it does/doesn't like.
Any pics of rigging, interior layouts, or handling tips would be great. Mine doesn't seem to have anywhere for a boom vang, so thought that was odd. Perhaps these boats just rely on tensioning the main halyard to flatten the sail?
Here's the one I recently bought.

Try this site;
www.trailersailerplace.com.au/
And John Crawford Marine has a good TS library but can only see the V de S 710
With the geometry of the boom and main sheet, don't think a vang will make much of a difference. Might I suggest you take it sailing a few times before you start modifying. Old VdS knew what he was doing.
Try this site;
www.trailersailerplace.com.au/
And John Crawford Marine has a good TS library but can only see the V de S 710
Yep, have been on TSP for a while, a great site, but not too much take on the same question...hence posting to SB.
And John Crawford had nothing as you noted.
I will take the advice above and sail it a bit before doing anything drastic on rig. In the near term I was interested in tidying up the rats nest of wiring inside, install a sounder, bilge pump, electrical keel winch, etc. over time, so was keen to see how people had set their interior up for quite a tight internal space.
Anyway, hoping this post might get a bite or two from the last of the MB21's :)