I recently bought a Primex 3008 and a Märklin 3012
in good condition but no box and without service manual.

My PRIMEX 3008:


These two wonderful models had been used a lot by their previous owners,
so they both suffered from the same trouble, for a time the unavailability of
a 7173 replacement pickup shoe.

Märklin old 7173:


Märklin old 7173:


So a same sized pickup shoe has bee used, but without the wide insulating part.
Both used the same recipe : solder the power wire directly to a 7185 pickup shoe.

Marklin 7185:


Marklin 7185:


This eliminating the thin fragile and breakable original contact plate between chassis and pickup shoe.
I did not know what was this contact plate .
Because I wanted these locos to be as closed as possible to their original set up
and because of the availability of a new corresponding pickup shoe 201570,
I started some small investigations on the original replacing parts of these models.
Searching "Kontaktplatte" on the web, I finally found some parts:

Tell me if I'm wrong, this part is designed as "20087"

Märklin old 7173 and corresponding contact plate:


Märklin old 7173 and corresponding contact plate:


Now the new 201570 pickup shoe:


The new 201570 pickup shoe:


So I've luckily found on Ebay two of these old contact plates.
And now you can see my two happy locomotives in their almost original set-up:
See how the thin contact plate is bending only with the pickup shoe pressing upon...

My Primex 3008 :


My Primex 3008 :


My Märklin 3012:


My Märklin 3012:


Hoping it will help...

Best regards

Joël