Yes I just did it on my 1971 Raleigh Super Course. It's not all that drastic.

I've used a wider wheel than the frame was made for but the problem with doing that is that the dropouts won't be parallel, so it's better to cold set it even if the difference is small.

And doing it yourself isn't very hard. Use the string measuring method. Bend with a long 2x4. It helps to have a second pair of hands with you.