Thanks, Bob. The camera, as I said, was a 1930 Nagel Ranca, a beautiful little precision camera, wish I still had it. I think it was called Ranca only in the UK, and Pupille in other markets. Mine was a bottom of the range Ranca with an f/4.5 50mm lens labelled Nagel Anastigmat, but Nagel bought-in all his lenses, mainly from Schneider, so it was probably a Xenar triplet rebadged. Up-market versions of the camera had a Xenon six-element lens or a modified Leitz Elmar.
It was a horribly grey, overcast day with on/off drizzle. I was standing on a balcony to take the shot. To get the depth of field I wanted I had to close down to about f/11 or f/16 and use 1 sec exposure IIRC (estimated combination, no meter). I was trying to balance the camera on the balcony rail when another amateur photog, kind soul, offered to lend me his tripod for the shot. I don't really remember how far away from the loco I was, probably about 20 to 25 feet from the front. I remember I focused - by guesstimation, no rangefinder - about a third of the way back along the boiler, about where the first 'ridge' is. I think the shine on the top of the engine boiler and the high contrast is because the thing was wet and shining!
It's the sharpest picture I took that day. The 1930s Xenars were capable of producing very sharp pics, and I'd rate them against any post-war triplet except that they weren't coated, so the contrast was a bit down. For most of the other shots I probably worked at either 1/25 or 1/15 sec with the lens almost wide open. Film speeds for fine grain black and white in those days were usually about 64 ASA. You can see the lack of depth of field in the second shot (I should have focused further away) and, I'm ashamed to say, there's just a touch of camera shake in the shot of Valerie. I wasn't a very experienced photographer 54 years ago, but with this shot everything came right! .