I am in the process of building a worsley works scratch aid.
I have quite afew spare motors taken form other things, I would like to use one in this build
either one on the right would be idea but I not sure if they are powerful enough

It depends how much want it to pull. The Nigel Lawton 6mm motor isn't that powerful and is 6v so needs care handling. It's also got no thrust bearings so can't directly drive a worm without additional bearings (I found that one out the hard way  )

Gearing and weight are more likely to be your limits - the bigger the gearing ratio the more traction you have but the lower the speed. The more weight *in the right places* the more traction, although you really want the loco to slip before the motor expires !

A trick sometimes used for very small locos, particularly in tiny scales is to make sure the loco is powerful enough to move itself and maybe a little bit more, and then hide a second motor in a coach. The egine then has enough welly to run around its train and light engine, and it can haul a long train because the train hauls itself !

If its a tender loco you can also put it all in the tender or a bigger motor in the tender and drive in the loco (or indeed vice versa in some cases)

I've always wanted to do a coffee pot like the ones at Beamish with the 6mm x 10mm motor - but I've never been able to figure out how to get the gearing in along with the motor vertically as the boiler

Alan