Bike frame worth building

Hello I have a 52cm 1970 Nishiki International with 27" rims and parts I picked off of a 1970's Schwinn sprint. I was wondering if it were worth building up, converting, modifying, upgrading etc. I got the frame for free from a church along with the other parts. I don't know too much about these bikes im kind of a work with what you've got spend little to no money kind a Guy and dont have much money to begin with anyway. Even though im cheap I still value quality and comfort and to be able to travel daily through the city and also go long distances if necessary. Otherwise I have come across a 60-62cm Manta frame idk if its worth switching or if its OK to stick with my frame being that I'm 6'3" and all but for all I care I could just raise the seat if it saves money. I'm wanting a rig somewhere in the lines of a hilly city commuter/ touring bike as well as for recreational use and fitness. What are some different options for these frames in regards to modern conversions and component upgrades like wheel options gears shifting etc. Is there anything worth doing with these frames? Thanks.