Oh, you can get a good sized quilt or blanket in there, a big,bulky comforter probably not.
I think those tubs can accommodate 12 lbs pretty easily. Mine gets 16 lb loads pretty often as the Three-Ring can easily roll it all over.
The Energy Ring on this one looks like it has seen a lot of use. These machines were pretty tough,though, so might not need a lot of work. For sure the inner tub has to come out so you can check out the inside of the outer tub and the Tub Support Mechanism.