Pretty close..
to the BOL and your model number is a bit off, but I found the breakdown on Sears.com/parts by using just the first few letters and numbers.
First of all, I think your machine has gotten something caught up in the pump intake area under that big shroud in the back of the tub.I would start there and remove it and see if anything like paper, plastic wrap or cellophane or glass has gotten in there and is blocking the water from getting into the pump.
Be careful since there can and often is some broken glass in there.
If that is all clean, then I would make sure that the washarm is not binding and is not turning freely by hand and that the pop up wash tower is free as well.
If they are, then remove the wash arm and let the machine fill up and run it with the arm off. You can run this unit with the arm off and not spray water all over the kitchen with the door ajar since the pump will send the water up in a thick column about 9-12 inches high. If the srpay is still weak, then the olny other thing that it could be is that something thru the years has gotten into the actual pump intake area and is clogging the screen that the shredder spring would spin in front of and water cannot get in to the impeller and out thru the washarms.
As far as all the Yibbles you get on the top rack, your machine seems to lack the upper spray arm that sprays water down on to the top rack. You can probably add one easily by buying the hose that goes from the wash pump to the top as well as the wash arm. I added one to my aunt's BOL machine and it made a world of difference. The pump actually had the outlet capped over and the hose mated right up to the pump.
I think you can salvage a lackluster machine here and still come out with satisfying results if you take the time to truly investigate the possible causes of your problem.
The breakdowns at the sears site as well as at GE itself are good tools that show the breakdown of the machine. Poke thru the various similar models and you should find the one with the upper arm I spoke about. Your machine probably has a cover screwed on to the top to prevent water from going out the hole from the inside, which is the giveaway that you can add the extra arm.
Do let us know how you make out.