My current thinking is that if I am preparing this dash, including getting rear section tidied up and smoothed out for the new mold then once I have the new mold it will be a simple task to pop out another rear section to blend in the new dash if I want to saving a fair amount of work. I will may do this but only after I have tried to fit the current dash and worked out how things are lining up etc.. I would hate to make two dashes that don't fit!
I also took a look at the two sets of gauges, they have the same perspex front molding and the main bodies are the same apart from the locations of the mounting points. So in theory ( and tested a quick test fit in the new binnacle) the old mechanical gauges could even go in the new dash.
I ordered off amazon a cheap and cheerful pulse generator and power step down module to try and see if I could emulate the VSS and get the speedo on the new gauge working along with the other gauge functions. I realise that without the ECU I can't get the Odometer and trip working.
https://www.amazon.com/gp/product/B008BHAOQO/ref=od_aui_detailpages00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B00LHBZCCC/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
This is more for fun and out of curiosity more than anything else. There is also the possibility of swapping over the chrome rimmed gauge bezel also.