I spent a significant amount of time last night researching how a player identifies a spell scroll, reads a spell scroll, casts from a spell scroll, and transcribes a spell scroll in 5e.
Identifying that what you have is a spell scroll is tricky since read magic no longer exists. I checked the entry for detect magic and identify, no dice there as to lay mechanics. I looked through the index of Wizard spells and didn't spot anything that would indicate it helps a player ID a spell scroll by reading it. I'm open to suggestions from the field. [Thus, my post last night re: starting to think that maybe I need a 5e DMG] Tentatively, I'm inclined to have you make an Intelligence (Arcana) check, DC 10 + spell level of the spell on the scroll.
I'm reasonably clear on how one casts a spell from a spell scroll. I don't have those mechanics on hand at the moment, but you can find them by googling. Or wait for me to post them later tonight.
Transcription from a spell scroll into a spellbook is covered by the PHB. Transcription takes 1 hour and 50 gold per spell level. As best I can tell, no Intelligence Arcana check is entailed in transcription. See PHB pp 114-115.
The main issue currently on our plate in the IC is discerning whether the vellum is a spell scroll or just some other spellcaster's scribbled notes. Let me know your thoughts.