I was just telling a friend at the weekend on the local club run about one of the nicest road bikes I ever owned. A 1960s Flying Scot I rode in the early 90s. it had originally belonged to the father of my (then) girlfriend who’d kindly given me it to train on as my own roadbike was in a shocking state and I was racing XC and he reckoned I was wasting my time training on a mountainbike. He was pretty handy on a bike and it had originally been his first criterium frame, It had an almost original Campag (super?) Record groupset (beautiful, light and really durable) the only concession to being I fitted a new axle and re-dished the rear wheel to allow me to fit an 8 speed Sachs freewheel on by splaying the drop-outs. I rode that bike everywhere on road and off, even up parts of the West Highland Way. I never raced it myself but did do a few TTs. years later I moved to live and work in Glasgow and through the city centre the handling of that bike really shone.. I still set my road bikes up with a mind to replicating that same handling to this day. Eventually it just became far too difficult to get hold of decent 27×1 1/4 tyres so I cleaned it up, serviced it and gave it back to it’s original owner. I bet he’ll still have it somewhere. Don’t have any pics of it, sorry. I’m just not one for taking pics of my bikes. seeing a pic might ruin the rose tint of my memories anyway ;)
You might have trouble fitting modern wheels to an older frame. it’s do-able but you need to remember not only wheel size but OLN and brake drops have changed over the years.
What bike is it you’re building? good luck with it, there’s usually a story behind every old classic bicycle so remember to ask whoever you bought it from to tell you as much about it as they know.