It's massive - takes up the entire dining table. I've updated the album so's ye can get an idea of the quarter-size scale.....!
Apparently, the design width between the frames is 4ft 8ins so my aim to have a spacer width of 17mm is well within what is allowable.
There was a photo that I saw on the old Photopic site showing the underframes and bogies hanging around the back of Inchicore in about 1975, but they may not have survived for much longer after that.