I need power to my second floor, fuse box help

My house i recently bought is an older house that was previously rented out as two apartments. Because of this i have two main fuse boxes (upstairs and down) the one downstairs is "on" powering the basement and the first floor but the one upstairs is shut off. Due to a poor credit score and a ridiculously high deposit wanted for having two electric bills in my name i was wondering if there was a way to power the upstairs box with the downstairs one. The one in use is full but im sure i can combine a couple fuses. I realize theres not much information with my question but i am just looking for a general answer and would be more than happy to provide additional information. Thanks in adnvance!

 

There is so much information missing for a good and complete answer such as how many amps are the two services rated for now. My first thought is to replace the downstairs service with fuses with a new 200 amp service with a modern circuit breaker panel and then feed the upstairs fusebox as a subpanel.

 

yes

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