I kept an Carver Silver 9T in its original package from 1993 to 2015 til its sale and the only prob was a light humidity inside the pastic bag, I had put not enough silica to absorb moisture.
I suspect a cloth bag would be better, expose the amp to sun in a dry day will help, good indeed is live in a dry area away from industry plants.
We have here a factory of dairies/milk processing plant to about 10km, after this industry began to run metal things as taps and windows began to rust and people who live by near have many health problems mainly elderly and children.

Thanks for the response FRM. Just trying to makes sure it outlasts me.. I guess. Sounds kind of tough with that processing plant causing issues.
Not much of anything like that here but good to know never the less.
Does your cat guard all of your gear?
JohnR thanks for your insight also. I will look into what to expect from desiccant. I have about 5 lbs remaining that I used to refill a dryer I had for my compressed air source.
I share your thoughts on the capacitors. I'll include a note to fire it up with my variac upon reopening. As for cosmetics most is anodized aluminum. Tube sockets are more the issue.
Thanks again everyone!