Identification of a Diesel Hydraulic

[u/IEnjoyEngineering]

It's manufactured by Walkers in Maryborough Queensland. I don't have any information other than it's a diesel hydraulic and these not-the-best photos of blueprints. It seems like a DH-4 but is missing some items and some proportions are wrong. Would love help trying to find out what model it is. I'll try to get more information from the friend who took the photos of the blueprints but that's as much as I can find out currently.

[u/IEnjoyEngineering]

To add it doesn't seem to fit DH class as it's a B-B config (four axles) Instead of three. And I believe it's seperated into possibly two bogeys

Edit: will also try and get the original photos from him so there's none of my flash