Can my cascadia (ISRI) seat tilt forward anymore?

Try looking at the front of the seat, base section just below the cushion. Never drove a crapcadia but the 579s and Volvos I have been in had a tilt lever in that area.

 

The seat pan gap is there because the last person to drive it adjusted it to that position. If there isn't a specific lever to move it pull up on the front of the base under the seat pan cushion and out at the same time. Or back at the same time, depending.

Don't know if all seat bottoms can adjust forward/back but never saw one that didn't.

 

Well I’ve drove Cascadias for years but idk. I’ve always tried to get everything back as far as it would go. I give you an A+ on the clean seat anyway.

 

May last 2 Cascadias had a seat-bottom tilt feature. Not all Cascadias have the same seat type. I only remember EVERY time I wanted to adjust the seat tilt It took me a while to find the lever, wheel, thing to make it happen. I can't remember. Look through the stack of manuals given to every new truck and look online for the manual if you need to. It's worth the effort. It looks like one of the pics shows part of the mechanism. I vaguely recall there is a gray plastic lever on the front just below the cushion.

 

I don't know. Can you put your fingers on the control that should pull/release the cable? I'm not sure if the issue is a fault of a part or a driver not knowing where the control is located. Both happen. Which would you say is happening? Look on underside of seat and put your hand on the cable and pull it. Does it allow the seat bottom to tilt up/down? Staring at things never fixes anything. It's ok to touch things to diagnose them.
The truck came with manuals for the engine, seat, radio, transmission, and other things. Many people throw them away or store them in a closet in a shop or office so they can't be of any use.