Commerical cabinet humi rehab-need a little advice

[AD720]

So I picked up an old commercial cabinet humi today. I drove around 90 miles each way to pick up pretty much sight-un-seen but the price was so low that I felt I could roll the dice.










Over all it is in pretty good shape. It's obviously no aristocrat. I'm not crazy about the angled shelves - I feel like I am losing a lot of storage space that way so if I can get this thing sealed up and it holds RH well maybe I will think about building some new shelves for it.


The problems I am seeing right now:

1 - The front glass doors seem like they are not sealing, mostly the left side door.
2 - The back piece of wood (could be Spanish cedar, it least it's not aromatic!) is pretty thin.
3 - There are a few small gaps.

I can probably lay another piece of wood over the back to thicken it up. I'm not sure what to do about the doors yet.

I went to Home Depot and picked up some clear, silicone caulk. Is that OK to seal the gaps and also to seal where the glass meets the wood on the inside? I am concerned about the odor.

Any advice at all is most welcome.