Welcome to the club.
My standard thoughts on selecting a Dandy.
Look at a few before you buy. You learn to see what is right and what isn't
Just as not all Reliants are Robins even though many think they are not all Dandys are Darts. The Dart or 4 is 4' in width plus wheels there is a Delta at 4' 10" and the Discovery and Designer at 5'10" one other reason for looking is because of this. 4'10" is a lot more spacious than 4' and 5'10 is another world altogether.
The unladen weight does creep up a bit as they get larger but they all top out at 500Kg gross.
Towing a Designer is 2
ths of bugger all more complicated than towing a Dart. You can just feel an increase in presence but as with all of these rear entry Dandys they are remarkably stable. You will never get a twitch out of one. You can read the threads on dynamics if you wish but the stability of the smaller Dandys is no boast.
Towing with a small car. Dandys were designed to be towed with small cars. There are a few towed with classic Minis. I shall be seeing someone next week in your neck of the woods who tows with a classic Mini. They are towed with 2CVs Reliants etc. Cazz and Wayne tow a 5 with a classic VW type3. The 1991 brochure says that you would need at least (Mini) Metro to tow a Destiny. The Destiny at that time was as per a 6.
Local trike company from near me and their display at the BMF Rally. Guess what else you can tow a Dandy with?[You must be registered and logged in to see this image.]
Buying an old one? The older ones with the more rounded roof profile are slightly easier to erect the awnings but the awnings are slightly smaller.
Options: The options amount to size, awning, internal heater and insulated walls, rarer is the option of skirts. Though there are quite a few one offs.
Is a Dandy for you? You must attempt to erect a Dandy. Though probably the strongest folding camper and certainly the one with the longest lifespan they are not the lightest nor the easiest to erect. Gas struts on the beds help and though it's not been done yet as Caz Numbers muses if a 6 can have gas struts to lift the wall why not the others? [You must be registered and logged in to see this link.][You must be registered and logged in to see this link.]