I have records of visits to Doncaster Works spanning the years 1973 to 75, all with the Dalescroft Railfans. I think there are 4 visits in total. Plenty of Class 31s around at the time. If anyone wants this info then please let me know.
I also recollect that we visited Stratford Works but this was an ad hoc add on to a trip around the shed so unsure what was in the Works as opposed to the Shed.
I have kept all my spotting books and have dates and info from about 1972 onwards, prior to that I didn't keep a record of the date just the location. Stupid boy!
Hope this helps