I set about removing the boiler in a gentle way... then I got out a pair of pliers and gave it a jolly good twist and off it came. Fortunately no damage done to the cab but the boiler now looks suitably second hand. I'm sure it will find a use in a junk pile or such like.
The bits after separation
I never had a way of keeping the body attached to the chassis with the old arrangement so hopefully one of the advantages of plan B will be in the form of a nut and bolt.
After a rummage in the famous bits and bobs box I found some boiler bits and bobs which looked a bit meatier.
Boiler fittings just resting in the above pictures but they look much more like the job. It does now have the look of Ivor The Engine's butcher cousin but I can live with that, better than an eight stone weakling.
On another matter entirely, the pictures below are of a 7mm model of Linda which was constructed as a gift to the late Allan Garraway. It has been returned to the railway to be displayed, once I have the details I'll post them. Its a lovely thing and apparently even the flat wagon is the correct running number for the one on which Linda arrived at Minffordd all those years ago.