Fostering/adopting BP from a rescue. Few questions

This is my second ball python and I am fostering him/her for now but will likely adopt. My previous Ball Python was rehomed due to an overseas move. I do not know the sex or age or any history on Zipper. I saw him eat a medium rat when I picked him up and he is very docile. He is 3.5ft and 1678g. Does this seem about right? Do you think weekly feeding would do or maybe every 10 days? Is there any way to tell the age? He also seems to be a bit darker in color than other Ones I have seen. I will try to post a picture

There's really no way to gauge the age on an adult. For a male at 1600+ grams I'd guess at least five years.

I have a normal male that size and he gets a medium rat every two weeks. He also fasts from about Halloween though Easter every year.

Thanks for the response. I think I will try at least 10 days between feeds and see how it goes. I am going to the rescue this week to help out and maybe another volunteer will have more info on him/her. His disposition is great so I think he must have been a well cared for pet at some time.

Agree that it's hard to tell as they grow at different rates. I would feed a medium rat every 10 - 14 days