They look like XCS141/Intermotor 22380 points to me - have a look on eBay. (Make sure the two lugs face outwards, though: there's another type with inward-facing lugs, and sellers sometimes mix them up).
Ducellier distributors like yours are great, as you can adjust the points gap from the outside. I wonder, though, whether this is the type originally fitted to your van. If it's a later one with the 'wrong' curves, it might be contributing to the running problems you're experiencing.
If you can give us these numbers:
-The Rxxx number on the body of the distributor. (e.g. R244D61)
-The number on the plate on the right-hand side of the engine.
-The oval plate number. (e.g. R1123)
-The year of production.
we might be able to offer a few more ideas.
Don't give up on it - I'm sure there's a solution!
I did post the numbers off the engine plate along with the pictures, I have been busy today, I cleaned the carb out for the fourth time and adjusted the timing slightly there is some improvement so once I get new points etc I will have another go at it. What points gap do you suggest ?I must have got my wires crossed somewhere - I thought yours was an early F4. I should have read the rest of your thread!
Okay, a 1985 F4. Chances are the distributor is the right type, but it would be interesting to have the number stamped on its body (e.g. R287D83) anyway, as well as the engine type number (on a plate on the engine block, e.g. 800 05/B1B).
Have you tried tweaking the points gap to see if if makes any difference to low-speed running?
You can buy those points on misterauto .They are pretty good for R4 bits .You need Valeo D309 and the roter arm is D911 it is the smaller number lower down on the page these are Ducellier ones.You need to look under the 1.1 engine heading. As said above thats a good dizzy you can adjust on a dwell meter with the engine running.