I too have looked through my books but have drawn a blank. I know Bovington do have tank plans but don't know if they have any of a Grant\Lee with the M2 counter-weighted barrel. I have found this clip of the holy Grant which does show some details of the counter-weight and may suffice. I am modelling a 1/35th Late Lee of the 3rd Carabiniers in Burma so have also been looking at references and have bought a barrel and counter-weight in that scale. Maybe I will do it in 1/6th one day

https://www.driving.co.uk/video/wwii-m3 ... lletholes/
All the best,
Will.