One or both of his sons will take the business on. As mentioned earlier €100k minimum is the starting point and the size of the market here would make it almost impossible. Some decent CAD drawings of any proposed model would no doubt get people to part with at least a 50% deposit. It must be money up front, as history dicates everyone is keen until it comes to parting with their cash. The market in the UK is massive compared to here, a good example would be the Kernow Class 205 Thumper DEMU's, a unit which only ran in a certain part of the UK, yet gained enough interest for a RTR model to be made by a major manufacturer in several liveries, albeit commissioned by a retailer.
The only model worth making would be the A class, with 6 basic liveries - but dont forget you would need 2 sets of tooling for original/re-engined with EMD headlight versions so that could well be €200k needed as people might not buy it if its not right - but then again people seem ok to part with cash for certain highly inaccurate models so who knows.
Re-liveries of existing models are of course cheaper (e.g IE Autoballasters) but the 3 major model retailers on the island simply would not be able to get the funding together to commission a RTR model. Im sure Model Railways are not the main earner for any of them (open to correction) but given the Model Railway only retailers that were here no longer exist its a case of make do with what is available/pending and appreciate it. If you have a six figure sum lying about and are willing to take the risk go for it