Problem with unknown Gauthier shutter

Pictures are from the shutter on an Agfa Karat 3,5 with an Apotar lens.
It's a Gauthier shutter with no model name anywhere.

I have cleaned the aperture- and shutterblades. In that process the screw (a little below and to the right of the middle of picture 2) with the spring on it had to be screwed out from the rear of the bottom plate. I put the visible end of that spring back, but I had no access to the other end, as I have not been able to take out the speed retardement unit. Now the shutterblades don't function as they should: They open a little while I tension the shutter probably because the other end of that spring is no more engaging the shutteraction ring as it should.

I will have to take out the speed retardment unit. I've done that on a few others in the Gauther family, but I'm stuck with this one.
How to take it out?

OK. I found out myself:
The speed retardment unit is screwed to the base plate from the underside! See first picture below.

This ain't easy.. the spring on the shutter blade ring is tensioned agaist one of the screws holding the base plate to the housing, so a temporary peg had to be put in to hold the spring in place while putting the plate back into the housing. The peg was then, of course, preventing from entering the screw, so I had to put in a wedge between the very end of the spring and the housing wall to be able to remove the peg and finally enter the screw.

Well.. But what can a poor man do but to try (and try again) once he has taken everything apart?

I keep wondering what name Gauthier had for this shutter? Was it made specially for the Karat 3,5?