Yes, they have the reverse dynastart but even if our friends motor has this it could still be a Britannia engine with a change of dynastart for use later in a microcar, then again it could be from a Tourette!
I fail to see the significance, at the end of the day its a Villiers 9e.
Indeed so, but it has all the correct bits for its installation, as not all 9E are the same. As such its an unusual find. Add the small bits of evidence that came with it. It just has to be worth following the records, if there are any, to see if this can be the engine from a rare car, or scooter for that matter.
It was actually bought as a suitable spare for a Scootacar. Maybe it will lead to a body without its engine stashed somewhere - Devon. We achieved this with a DKR Manx years back, I found the bike, sold it to a collector and later found the correct engine. To say he was pleased is an understatement.
For me, any proof of it being Progress means I would be looking at a faithful reproduction of a car I long rather liked the look of. Its a third original being engine/chassis/body in simplicity. If the ID was found even better. Puts it level with quite a few Tigers etc.
Google produced nil on the Progress Britannia. I seem to recall an attempt to Villiersfy the Sachs powered Storch, which was the basis for the Progress and Tempo, among other badge engineering efforts, to market the German original into home markets. I did find a Progress Anglian posing in front of a Tourette at the 1956 motor show. That looks more like an Adler? is it.