Below we see a DG soldered onto a small brass block that is a tight fit in the NEM coupling pocket housing on the chassis underframe moulding. It is drilled and tapped 12BA and blackened. The screw is a countersunk one, also blackened.
The only modification is to drill and countersink the bogie keeper frame for the 12BA screw. The New DG coupling just drops into the pocket and nips-up tight with the screw. The coupling height comes out just right at the 4.5mm measurement above rail height that I use.
I originally purchasesd a split headcode 37 and a centre headcode one as well. Unfortunately research showed that the centre headcode ones did not arrive on NE Region until after Pool in Wharefdale closed in March 1965. Thanfully Andy Hanson was wanting a centre headcode one, so he purchased a split headcode one and graciously did a body swap with my unwanted one. Thanks Andy !
Next job is to carefully remove the existing tampo printed numbers and renumber them as Thornaby based machines. I've seen two approaches to doing this, cotton buds dampened with meths or T-Cut applied gently with a cocktail stick. I'll let you know which method worked best for me!