Robert,
I have looked again at the photo of '7352 which John posted.It appears a lot bigger now by the way,I'm sure,if you click on it.
If I understand you correctly...the old shed,as I knew it,is just out of picture to the right of the breakdown train,which you can just see the end of as I said in my last post.
At the back of the old shed (ie. the south end),and attached to it,was the fitters shop and the general office/shedmasters office,all in the same brickwork. The two offices were quite small really ,considering their importance.There are odd glimpses I'm sure of this area in some photos in John's "Returning to Grantham" thread on the LNER website.
Above the time office's roof (which I refered to) appears another higher roof,which I thought at first was the front of the "new shed",but I think now it is the roof of the boilersmith's shop,a brick building,quite high and standing on slightly higher ground,which also accomadated the firelighter and boilerwashers in small messrooms at the rear.Whether that building existed in the '30s.I don't know;I rather think it may have,with the brickwork and age of it,as far as I can remember.
By the way.I've just thought,there is a good photo or two of the general/shedmasters office,taken from the old coaling stage area,in the early '60s ; I'm sure it's in Colin Walkers book "Eastern Region Sream Twilight",can't remember part 1 or 2 ,but I think it's the one "south of Grantham". Hope this is of some help.
Regards , Roy .