Ahh, yes! I am familiar with the usefulness of baby wipes when it comes to cats!
I have the opposite problem with one of my 14.5-year-old orange tabby sisters - I'm trying to put weight on her. But her sister has no such problem, that's for sure!
I hope your vet has some connections and can rustle up some senior food for you. These shortages are getting very old very fast.
Finally found some senior cat food, 2 brands, at PetSmart . Will start the transition tomorrow. I'm hoping they'll like one then will order a few cases! I was amazed at the inventory PetSmart had...much, much more than either Petco or PetFoodExpress. And talked to the vet and she said, no kitten food is not an acceptable substitution for senior cat food.