Seeking mc recommendations

The Dual has a light arm. You can always add mass to an arm to accommodate cartridges with less compliance but in the case of the Dual adding mass is not a good idea as this may affect the longevity of it's automated functions. I think AT's -OC9XML would be a good fit

I’ll check it out.  Thank you !

I had that Dual in the 70s with a AKG cartridge it was my first turntable after my Loddys all in one system

Get an Audio Technica VM750SH and try it on both the Thorens and the Dual. Then sell the Thorens. I don’t think you’ll gain much trying to use a cheap MC on either.

The Thorens was a gift from my wife when I started in vinyl. I won’t sell it. I’m interested in experimenting with the Dual since I don’t care for the sound of the Shure M97XE that’s currently on it. I understand what you mean about a cheap MC cart. It would probably sound worse. So the bigger question is : is the 1229 worth putting an expensive cart on it ? 

The Denon DL-110 would be a good choice

Nice of her. I had a 318 and found it warm and forgiving but it killed the music and lacked detail. The Dual CS505 buried it for half the price back then. Even spending $250 on a AT540ML or 2M Blue will give you an improvement over the old Shure. I don't think the headshell is up to much on the idler Dual. Can you change the arm? 

Yes I could change the arm   That would be a fun project