The Classic Machinery Network

I have a question about the correct hydraulic oil to use in a Ransomes T51D bat wing mower.

I noticed in the Ransomes 951D manual which is slightly newer but very similar to the T51D that the recommended Hydraulic oil can be either 10W/30 oil or Turf Protector. (see attached image)

Anyone have any ideas on what is a good oil to use for the hydraulic system in these mowers, as these machine comprise in the main hydraulic motors for wheels and the decks. Is the recommended 10W/30 oil just regular motor oil?

I have being reading about 10W/30 Super Universal Tractor Oil. It could be a good option perhaps?

Generally speaking if the 10W30 oil is to be used for hydraulics make sure it's a straight mineral oil, not a modern synthetic or anything with detergents added.

I wonder what would be wrong with a dedicated hydraulic oil? Cheapest oil compared to engine and transmission oils.

Some machines don't seem to have the seals or pumps for it. It's really odd, the Yanmar YB201 we were borrowing, before I bought the JCB, for instance, had labels in the cab, on the chassis plate and the hydraulic tank, and repeated in the service manual too, making it very clear 'DO NOT fill with hydraulic oil!' and to use 10W40 mineral oil only. Anecdotally I had read of people ignoring this and then ending up in a world of pain having to pretty much replace everything in the hydraulic system, because it resulted in just about everything leaking or poping a seal.