I have a lord suppers picture in silver picture with wood frame. 24x13

What is the picture made out of? Sorry I wasn't sure! You can touch up the wood easily by cleaning it with warm water, a soft cloth, and a bit of mild soap. You can also stain it if you want to update it a bit - this is a great natural stain! https://www.hometalk.com/diy/paint/homemade-natural-effective-diy-wood-stains-9654179?expand_all_questions=1

I would ask a service that cleans houses after fires. They have a dry sponge you probably could buy.

Wood frame should be stripped and restrained or painted, can never get rid of the smoke smell otherwise. No ide on the picture itself, sorry

I have cleaned many pictures using the "wallpaper cleaner" method. Ball up day old bread slices , stroke the bread over the picture. Unbelievable how the crumbs just fall off and take the dirt with them. May take 2 or 3 attempts; but it works. Keep a plastic bag handy for the debris.

Brilliant!