These sockets have the right size: mounting holes 38, 2 mm apart.
They are sold in a set of 3 pieces only. The sockets are NOS.
These sockets are becoming very rare. Traders know that, too. Check on e-Pay what they ask for them.
I drove 3 hours and 250 km at € 1,89 per litre gasoline to find these under a table at a radio flea market, .
New Old Stock: 1 set of 3 pc.