I believe Patricroft closed as an operational depot in July, 1968 (maybe 3rd of July? Someone here will know.) Certainly I 'bashed' the shed in late July, and there was no obvious activity - just maybe 25 steam locos, all dead.
It may have remained as a signing-on point - so yes, he may have become a second man after steam finished.
People around at that time are disappearing fast these days, as you will be aware, but there was the interest in the last workings was very intense. Another site you may find worth visiting is Lostock Hall - let me see if it's still online
Yes - go here
www.prestonstation.org.uk
Obviously it's a different shed - but people on there were almost all involved with the last months of steam, which includes Patricroft, so there is a lot of knowledge on there. Catch 'em before they go too.
The story goes that the shed foreman at Patricroft were dedicated enough to make sure his best Standard 5 4-6-0 was transferred to Carnforth for another month's work in traffic rather than rot at the depot awaiting the cutter's torch, so you can see people (some at least) cared about their job. It was the last one in service.
Edit: I see you asked what types he might have fired. The types of loco at Newton Heath and Patricroft changed a great deal between 1956 and 1968.
Especially up to about 1962 (there is no specific date, of course), but up to then there would have been a large number of pre-grouping locos around - things like the (rather lovely, IMO) Lancashire and Yorkshire 2-4-2Ts. I presume these would have been largely relegated to lighter services by 1958, but I don't know. Maybe they still worked some peak hour trains towards eg Man Exchange - Blackburn.
There would have been ageing Aspinal 0-6-0s and stuff like that too.
I think Newton Heath had a number of Jubilees, later Scots and standard Britannias for Manchester/Liverpool - Glasgow/Edboro services until about 1965 or so.
I think Patricroft was a more 'mundane' shed, without any 'glamour' express turns like N Heath. Certainly towards the end it was largely Black 5s and Standard 5s - I think these maybe worked parcels and semi-fasts and stopping services towards Liverpool - not sure if they worked over to Leeds, or if they were Newton Heath turns.
I think Patricroft had quite a few of the Caprotti valve gear Standard 5s, which had slighlty different driving characteristics to the far more common Walschearts motion. This was a late attempt to improve the efficiency of the steam locos. I suppose it had 8Fs too, I can't remember.