You can chop up her "baby" but only if you really want to? Those old Town Cars are real cheap. And there's a reason most of them are rolling around looking like they've got lowering blocks in back - the "air bag" system sucks big time, and is just about impossible to repair point by point. I'm pretty sure that the differential in the '85 and up is the Ford 8.8", which is a carrier type with rear cover vs the pumpkin type third member on the 9".

I'd shop for one on your local CraigsList, but run it by her before you hand over any money to be sure how she feels. Cold nights sleeping alone, unless you've got a dog.....or two.