Am enjoying the suggestions and speculation here - it’s a great read!
Further musings from me:
* I don’t think that the location of the event necessarily indicates that something GNR will be launched. The venue houses the priceless Fry collection, which represents virtually every single railway which operated in Ireland, so I think that makes it an appropriate location, whatever the new locomotive will be.
* Fran’s use of the word ‘ambitious’ is still the clue here - it could refer to a complex prototype, so the 800s might well fit the bill (anyone for a 3-pack boxed special edition?) or it might refer to the complexity of the project, in terms of the breadth of versions and liveries being made available, although that is pretty much the case with everything IRM/AS does, so I’m guessing it’s a complex prototype.
And just when you think I’m being uncharacteristically sensible, I’m going to suggest that as this year is the 150th anniversary of the opening of the Belfast Central Railway, perhaps we are going to be presented with a BCR train pack, limited to 150 pieces.