Remove the tubes and scrub the chassis with
an old toothbrush and some cleaner after blowing
away the loose debris...

Be careful not to get any liquids into wafer sockets.

The cabinets might need to be repainted, they look pretty gross.
If the front panels are good it would be worth the effort.

Too bad you weren't able to rescue those a few decades
earlier! I would do what I could to restore them if
they were mine!

pete k1zjh