Dawes Galaxy is a classic, lugged steel, what a deal. Looks like it could do with a good clean and lube though. You might think about changing the cassette, chain and chain rings. Your wheel is 27", or 630mm, but you'll be able to use 700c, 622mm diameter wheel, tubes, however, 27" (630mm) diameter tires are not stocked by many shops. Ride with a couple of tire boots to repair your tire. At some point you might go to 700c, 622mm diameter, rims. They should work fine with a small brake alignment. This is a great project bike!!!!!