Hi,

I have a number of various Model 15 components. 2 Bases, 2 Printing units, 2 keyboards, 1Tape distributor, 1 case and 2 keyboards for tape punching.

All are far from perfect but appear complete. I do have access to a large range of NOS spares.

My task is to refurbish and produce a complete working system.

At present I am trying to decide which base unit to start with and I have noticed considerable variations between the two. 

The unit in worst condition is marked 15C and is fitted with a terminal strip marked 21-46 and is equipped with the holding type magnets. 

The better unit (marked BB-44 on a brass plate) has three terminal strips with six terminals each and is fitted with a line relay and circular (puller) magnets. There is also a 4 terminal socket arrangement adjacent to the fuse, nothing connected.

I have a schematic of the standard 15C base but cannot find a schematic of the other. Is anyone able to point me in the right direction?

Thanks