Unterbody parts for Interurban cars

3D drawings of resistor bank and brake cylinder scaled for H0 resin printing

Interurban motor or trailer cars has numerous unterbody parts to be reproduced at an appropriate scale for H0 models. Historic car diagrams often not help, because the carbody builder generally ommited the electrical and pneumatical parts in their drawings.

Also, the old traction model pioneers like Fritz Hardendorf were not always so exact when drawing underbody parts. Looking after your old Suydam models is not helping too : resistor banks of Sudam models are clearly oversized, as an example

So you need to search other sources. The Council of Tramway Museums of Australasia has probably the best technical online library http://www.cotma.net.au/library/ in the folder "Westinghouse" or "General Electric" you can find some rare pearls.