Noob with 1940 9N lift problem

Hi everyone. Nice looking forum. I run a similar forum for Moto Guzzi motorcycles. Anyway, not here to promote my site, but to introduce myself and ask a couple questions.

I just recently acquired this 9n so I could do small jobs around the house. After a bout with the electrics and rebuilding the carb, I finally got this thing running like a top.

Now, I cannot get the lift to work at all. The PO said he thought it worked when he parked it 3 years ago. Here is what I have did as far as troubleshooting goes.

I have drained the yellow and watery oil from the tranny/pump/diff cases and replaced with new 90W GL1 from TSC. Still no worky.

Then, I pull the access cover and work the control arm up and down but see nothing moving. Shouldn't something be moving when the arm is moved up/down?

The pump works as verified through a successful PTO test and turbulence seen through the access cover with engine running and pto engaged, so I believe the pump to be ok.

I bought the F04 book and read through it, but it really can be a little confusing to newbie tractor owners. Motorcycles are easier

Would it be best to pull the pump and give it a go over? This will be my first bout with hydraulics. I also have a Terramite t5c backhoe that has given me a little experience in the tractor maintenance world.

Anyhow, I would really appreciate some ideas on what to check or test next. Even after changing the fluids, it still looks a little bad, so I think I will drain it and replace it again tonight and maybe flush it with diesel. I don't want to to this often at $50 a pop though.

BTW, pics to follow.

Thanks,
Luap McKeever