That generation Railmaster is a lovely watch. I owned one albeit, briefly and thought it was fab. Super legible, nice vintage vibe, great lume and you could spend days trying it on different straps. The timeless twisted lug case suits the simplicity of the design perfectly.
Mine was the 39mm and at approx 7.1 inch, I would regard my wrist size as average. As with any watch of this aesthetic (all dial, thin bezel, Explorer 214270 fits the criteria here too) they do wear bigger than their measurements suggest. Not sure how you're packed in the wrist department but should definitely be considered here IMO.
As you say, the 36mm version is very seldom seen but could be the best of the lot.
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