Samuel Pinky Bradovka

I just picked her up this past weekend. Needs to be rebuilt and what not. was wondering what tank upgrades i can get for it? Since i plan on riding her for a while to save money on fuel, but the tank with it is very tiny. I was thinking of putting a 7L Honda tank onto it. Or would this not work? I'm new to the whole rebuilding of bikes but am a quick learner so this should be fun . if anyone has links to helpful info or tips that would be helpful

Well i know for a fact the Yamaha XT 200 i just picked up on the weekend only has 8 digits which are 15x - 000388. Not sure what year it is 1982-84? As it sits, it is in pieces but just needs a rebuild so this should be a fun project . If anyone can give me tips or links to certin things i may need to know that would help nicely, I'm 18 and this is my first rebuild. I'm very excited! Cheers!