Wallis steevens oil bath to measure and model

[Rob b]

Hello
I am wanting to build a 4” scale wallis and steevens 4 3/4-5 ton tractor I live not far from where they were made. Ideally I would like to find the owner of a late tractor that’s willing to let me do the necessary to photograph and measure everything practical to be able to build a model. I understand that’s my ideal but would consider anything from a pile of bits to a non contact measure to get the proportions. Or do you have an 8 ton roller with an oil bath engine or just some good pointers to get me going.
I have not yet been to reading to see what drawings are available
Thanks rob.