cheers
@StuAff. Not sure if I should be posting it in the vintage section. I was thinking of sending the serial no to Dahon for some age info but maybe won't get as specific as I hoped.
It shows the early signs of the 'good' Dahons about now and with a few niggles I think will be a useful hack about bike and folder for Mrs SBIB (she's warming to the idea of my rescuing another stray bike now that she gets to play on it

). The folded package doesn't lock together (that I've found yet) so I'm using a bungee cord across the rear wheels to keep it from flapping - it also has a bag to go in but its a bit of a strain on the zip with the rack on
A few pictures of it now fettled slightly and cleaned up. The rear dropout is rather bizarre, it drops out backwards along a very long channel which butts the wheel hard into the fixed metal mudguard & the rear fork clearance is minimal vs the hub, but the reap piece of magic is that the rear derailleur hanger is part of the dropout & axle set up, the rear mech has to be completely removed to get at the rear wheel and to get it back together in the comfort of home was a job that could have benefitted from having a 3rd hand, I wouldn't like to try it out and about
I'm taking a few rear precautions with a puncture proof tyre liner and slime tube to hopefully mitigate the chance of a walk home with a flat rear. If I like it, I may invest in some decent tyres for to help that along. (note to me: check Schwalbe and Conti for 20" tough rubber).
Folding it is dead easy and the levers each lock in place with a plastic catch. The collapsed package is barely bigger than my Brompton & weighs a fraction less too.
anyway Pics for them's thats interested: NB - since taking these I've changed the saddle to a Brompton one and changed the pedals rot a better set of folding ones I had spare.
In riding trim
the rear dropout of doom - the stand is mounted onto the other axle and comes off totally too (no biggy that though)
folded: trial and error has shown me that in these pics the pedal is in the wrong place - the drive side one should be to the floor.
compared to Brompton & with new seat & pedals added