the link is :
but acces to the archive seems to be donw tonight.
The Paddy Malon collection is catalogued as PP00206 - so search on this and you get a lot of references / files.
The raw material is not online, so you need to go to the archives and just plough through the drawings etc.. I think Paddy Malon was an engineer at the works and collected a lot data. some of the lots are bundled drawings, so lots have smaller number of items in them , so they are better decsribed.
A visit is probably best, they reply quite quickly by email, but I've not yet managed a visit