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The "B" End of the STL&BM 48' Gondola which Martin put out as an extension kit to his early MoP kits is shown on Page 219 (Figure 225) of the 1940 Car Builders Cyclopedia.
It has what appears to be an interesting ratchet type hand brake and looks to be mounted close to the car end center, just to the right of the retainer valve. No side or end ladders, all grab irons.
Perhaps Richard can elaborate as to the type of hand brake this was.
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