Kitchen Large Electric Appliances - Older dryer coils

I have a RCA electric dryer we bought in1991.Model DRB1555M. Besides a timer switch I replaced 6 years ago because it would would sit there and lightly buzz at end of cycles without clicking the last little bit to off position, it has worked fine. Lately it does not seem to get as hot as it used to at times. It has the two round coil heating elements in back. The inner coil does have a brittle spot near one of the round guide rings. Is it possible for the larger outer ring to heat if the inner one does not? One of the replies I read on this site mentioned intermittant problems with broken or hot spots in rings. I believe in preventive maintainance so I vacuum the venting areas at least once a year(also do my coils on my refrigerators at same time)I vaccumed it when I had apart a few days ago as well as resetting all other connectors around the drum and inside the control panel. It worked fine for a few days but is back to occasionally not heating as much.
My main question concerns the coil connectors. Mine are a blade type , but when I put in my model Numbers at repair parts sites the picture of my part comes up with round screw connectors. Are the round ones going to fit thru the ceramic base my blade connectors go thru now correctly?
A friend who is more electric minded than I am is going to try to come over sometime this weekend and put his meter on some of the sensors and connectors for me. I thought I would get the coil connector problem answered first.
I have looked in this site for years but this is my first time posting, hope I provided all info needed. Thanks for any input.

Hey,
You need to look at your wiring diagram and see how much resistance it's suppose to have on your coils.If the machine is that old it could be time for a new set of coils.

Regarding your spade terminals; the replacement coil will come with new terminals. Just cut off the old ones, wire nut the new ones and your done in a snap.