Spain, Cuba, Panama Revenue Identification Help

I would consider the cancel forged and out of date.
Cancel Types 58 & 59 long oval cancels like on your stamp.They were used until the early 1860's ,but no farther.Other oval types appeared
after with different forms..

Cupram,
sometimes, we have to step outside SCF, and search for specialist knowledge, this, I believe, is being a "Philatelist"
Then come back, and impart your learned knowledge here.

Information on Cuban revenues is very difficult I find, I take some information, from the Philippine example, and by Fulcher.
1938? perhaps a difficult time, and mixed franking was tolerated for revenue?

Nice covers, worth taking the journey to research.

Thank you Perf12
You confirm to me what I already suspected about obliteration.
I have not yet found information about the functioning of the postal system in Cuba during the war or immediately after.
rod222-if I find something I will come back with information.