As I think you could tell from my last post, I had drink taken.
Lot more sober today as I discovered that the metal plate is secured to the bar with 4 spot welds so I am not taking that off.
I have decided to make up a metal plate and pop rivet it to what is left of the old one just to get me back on the road until I can source another one. That plus a hole that can be bolted through where there is no metal left at all.
As you can see from the pics, even sorting out a template has been a total nightmare. I have precisely one half of one hole intact on which to base where I put the other holes to secure the motor in the right place.
But luckily a certain amount of the original plate came away with the motor, so it has been like a jigsaw puzzle with most of the pieces missing.
I have described it as being like one of those things the archaeologists do where they look at a minute bone and then tell you that the creature was 16 metres long, 4 metres high and had green eyes!
The central hole where the rubber grommet sits that keeps the motor free of wet has been a nightmare. I had no idea how big to make the hole. Obvs the grommet is going to be a tight fit, I had to experiment for ages making holes in cardboard, fitting the gormmet and seeing how much it moved. I now think the hole should be 28 mm.
Anyway, went to drill the holes in the metal only to discover that the drill batts, both of them, were flat. so packed it up for today.
Nothing has been helped by the weather as it has rained constantly since the middle of last night. Luckily I had put an old plastic type table cloth over the work area. Not totaly efficient, but good enough.

I'll chase up a replacement Monday, and thanks again all of you!
Cheers!

Well I have found a replacement from the bloke I hoped had one.
It isn't brilliant but at least the mounting plate is intact although rusty on the back.
Other parts of it have problems but none I think that would give way in the near future.
I'll fit it once I have derusted the plate and a couple of other places and painted it. It'll do till I can source a better one. If that proves impossible I'll take both back to the UK with me and drill out the spot welds on the plate mounts on both, then weld the better plate onto the original frame.

I'm also going to try and glue the two bits of the pelum together and use silicone sealant to make some kind of a join in the seal bit.
There seems to be two schools of thought as to how important the seal between the windscreen and the plastic parts is. And all I can say is that the worst rust by far was directly under where the seal had split.
Cheers folks!