I ran the crap out of a Walden back in 1982 in Colorado. Was working for a western slope asphalt outfit and we used that loader for everything around the paving spread from excavating to cleanup to charging the paver. I see a lot of outfits today using skid steers with paving spreads, but they travel so slow compared to the loader.
This one had the Ford industrial smoker -- er -- I mean diesel engine. Hydrostatic drive train, and barely any brakes. This one would load tandem dumps albeit carefully. Had quite a bit of break-out force, but lift was slow. I'm fairly certain it was the 4500 model.
When we paved the new Union Oil refinery in Parachute, I carried tons of asphalt into the plant with it around all the piping and other stuff in the way of the paver. Had to charge the paver in many places because the trucks couldn't lift their dump boxes high enough to dump into the hopper. (overhead pipes and catwalks in the way)
It wasn't a bad little loader other than it would bounce like crazy going down the road at full speed, was very noisy, and it did smoke like crazy. Two 4500B's sold a year ago in Texas at Ritchie’s, one went for 3000 bucks, the other for 800 which was a parts only sale.