Also I think you should archive and store this historical
BTC item better than in a frame. I am sure those clips hodling it will leave a mark.I cringe when I look at them.
Also exposing paper to light am sure does not help either. Stamps should never be left exposed to light..so neither should newspapers.
This article might help you in archiving it properly.
Preserving | Archivally Storing Old Newspapers Paper Art Damage 101: Types of Deterioration and Improper Preservation