I went there to have a look around in the late 70s, with Bill Shaw, then the Countryside Warden for Tong-Cockersdale and leader of the ‘original’ TCV (Tong-Cockersdale Volunteers).
The BTCV (ie. you) were looking to move from their old northern HQ on Copley Road, Doncaster, and I believe Bill had suggested the semi-derelict Hollybush Farm, hence our reconnaissance visit. I say ‘semi-derelict’ but it was still in a pretty reasonable state. I’m sure it’d have been knocked down though but fortunately, the (B)TCV did move in and there you are!
I remember the Whitbread brewery just across the canal was in the process of closing down at the time.