Time for some preventative TLC...
Ahhh, Penncrest. Neat stuff. The washers were more like the Hotpoint as they usually came with a self cleaning lint filter and the 'Agitator within a agitator' with that odd lock ring that had a habit of breaking.
All those are good things to check but I'm also thinking that you may have a bad heating coil. They come as restring kits and you thread the coils thru the ceramic eyelets, replacing any that are cracked.
I seem to remember from my GE days,(GE guys PLEASE correct me if I've forgotten something...) there are screws that secure the top to the front panel that can be seen when you open the door and look under the brow. Lift the top up and you will have access to the innards and will see screws that hold the front panel to the cabinette. By the way, you CAN check continuity of the elements and high limit stat from the top. You should see three terminals on the side of the 'can' or element housing. Remember, there are two elements that both share a leg at one end. With the wires removed at the terminals, you should get continuity between all three terminals and not to ground at all if the elements are good. Before removing the front panel, make sure you write down the location of all the wires at the door switch. On the back of the dryer in the middle is a small cover which hides the rear bearing. There may be a small keeper clip and some spacer washers you will have to remove off the bearing shaft (so they don't disappear into the dryer) before pulling the drum out from the front to access the elements and such. Undo the belt and out it should come.
While it's out you will need to check the front glides to make sure they aren't almost (or completely) worn thru. These can be rebuilt with new felt and slides or just replaced as an assembly, bracket and all. Also, when the drum comes out, there should be a teflon hub that sits on the rear bearing shaft. Sometimes it stays in the hole when you pull the tub. Either way, if it's worn, replace it. Of course delinting it is a given. All these parts should be quite available. If done properly, the average OLDER style GE dryer should run quietly and for a long time.
One trick I remember when restringing the elements was to put one end of the restring under my foot and gently pull on the other end to stretch the element out evenly before feeding it thru the eyelets. I just don't remember how far to prestretch it without over doing it. Maybe someone else will remember...
Hope this helps...
RCD