He has permanent Tongues which solves one but not both of those problems.

Well, if he can puzzle out the handwriting then Vanyel can try to interpret what the magical terms mean; Urtho also apparently wrote in a frequently-abbreviated shorthand that's pretty obscure to someone who never even met him. 

"Should we copy it or something? I have a feeling some of this could be really valuable but I don't think we have time to read all of it and it feels weird to just take it." Shrug. "Though I guess I'm not sure why." 

"Are we okay with using our magic here, there's a cantrip for quickly copying books."

"I think it's fine, if it's going to be lower-energy than my light anyway - there aren't any wards in here, I guess all his defences were further out. Some of the magic projects might be a little unstable, since they're incomplete, but at a glance, I'd have to raise a Gate next to one for that to actually be a problem, and also most of them aren't powered anyway." 

"It's a cantrip so it's very little energy." And he can pull some blank notebooks out of his bag and copy things, one page at a time.

There are maybe a hundred total looseleaf sheets scattered around the room (they're individually very dense.) 

Then it will take him about fifteen minutes. He hands Hagan the map to mark the latest rooms while he does it.

He can't label anything but his mapping is very neat and precise.

"Do you always draw maps of everywhere you explore? That's a good idea."

Vanyel is poking around looking at things with mage-sight. "...Ooh. I think this is a focus for a paired scrying-spell, I didn't know that was possible." He points at two hand-sized wooden boxes, the lids flipped up to reveal matching mirrors on the inner surface. 

"Ooooh, cool. We have that but I don't know anything about how it works. A lot of places, not mapping neatly will come back to bite you. It's also a good way to catch missing rooms."

"Though that's less true in a wizard's tower, unbounded as we are by petty mortal concepts of space and time," he says, still copying.

Vanyel chuckles a little to himself. Keeps looking around. Most of the other magic artifacts are a lot less scrutable. 

Secret doors or trapdoors?

There do not appear to be any further secret doors or trapdoors from the secret room, at least not any findable ones. 

Ah, well, can't have a secret room in every room. He'll also check the staircase carefully, on their way back up.

There are totally THREE different hollow steps, which can with some grease and Fetching be opened to reveal tiny compartments with very old notebooks in them. 

Hagan likes this guy. Aside from his decision to destroy the world trying to kill Leareth, that seems a bit iffy. 

Mahdi can copy those too, if they're still in readable condition.

Well, the handwriting is not any more legible, but the ink is only somewhat faded and the paper itself seems perfectly preserved - it actually looks like it's not precisely paper, it has the strength of cloth. 

He only brought ordinary paper notebooks to copy them into, but they'll do for now. "Do you suppose the pharaoh will pay us," he says while he does that.

"I would assume so! He is a pharaoh of Abadar."

"What, is he going to buy copies of this off us? I don't think it'd even be useful for your world's kind of magic." 

"He wanted information on Leareth. I guess if this is all just notes on magic it's pretty useless to us, but presumably he had a diary or something somewhere."

"Mmm, probably." 

And they can head back up to the room with the lift and the presumed-superweapons. Are they labelled or anything.