PekkaNF,
Reverse engineering was difficult but not insurmountable....
First, determine number of slots in armature, count number of segments in commutator....
Then cut off the rounded ends of the windings...punch out the wire in between the slots, put to one side at least 3 sets.....
Clean everything up.
To the wires, count the number of wires in the 'clump'.... Then take an individual wire and carefully measure its diameter....
Now we know how many turns per 'coil' and wire gauge....
If the commutator is removed, ensure its position is noted relative to rhe comm stack....look at the slot and the segment relationship.....
To be honest, I watched various Youtube videos and trawled the internet for bits of information before embarking on the winding..,,,