Martin, I built the Wemys pug when the kit first appeared. I bought mine from Pete at one of the Hslifax shows. It was a real quickie and was built over the next weekend. I did make new steel coupling rods for it and spring all the wheels but everything else was as per the kit. I don't remember having any problems with the smoke box. My biggest compromise was to paint her black instead of the WPR lined brown. As for crankpins I almost always use 14BA as the nuts are much nearer scale. Only time I use 10BA is if there is a return crank or on the recessed one behind sidebars were I turn a special and lock it with a Romford nut in a recess at the back of the wheel. The photo is of the pug crankpin, taken on the phone so not great, sorry! Ian.