Zetor 3011 dynamo regulator cut out box

Hello all I'm new to all this forum business and hope i have done this right!!!!
Basically i have my dad's zetor 3011 which was his 1st ever tractor he bought in the early 70s the year of it is 1968 I want to restore this to it's former glory first stumbling block is the dynamo regulator cut out box
I'm after a wiring diagram so i can fit it . I bought a new regulator box but it has only 2 coils in the box where the old one has 3 coils this was removed by my dad and unfortunately he passed before i could get any information
Any help would be greatly ​appreciated
Thanks for taking time to read my post

long time since i played with a dynamo but as far as i can remember 2 and 3 coil ones are interchangeable.

should be a thick and a thin wire from regulator to dynamo
think the thin will be labled f or m , the thick probably d and may be a larger size connector as well. will be a thick wire from reg to battery probably labled b. may be a regulator to earth wire or it may earth through the mounting bolts. might also be a thin wire to an ignition light