We finally bit the bullet, the one that involved figuring out how the mice were getting into the cabinet under the sink. That wouldn’t be so bad, but the cabinet maker (aka The Botanist, who has never much enjoyed involved indoor projects) elected to make the space continuous from there to the major portion of the under-counter space around the corner.
As to the fixing, carefully cut pieces of window screen, paired with a big swath of 1/4″ hardware cloth, all stapled with abandon, and ingress opportunities are…zip-zero-zip.
JCB got the space cleaned, and I will work on swabbing down the rest of the contents tomorrow morning….