Having the fork blades aligned
2cm seems like a lot to attempt to fix this way. I would not trust this repair to just any old bike shop, but find one that specializes in working on older steel bikes. I'd expect to pay for about an hour of labor at whatever is the going rate for the shop.

I have attempted to do this kind of repair on a fork myself following Sheldon's directions and it's not that easy. Even a relatively minor alignment tweak is difficult to get correct. 

The other alternative is to contact a local frame builder and see if the fork can be rebrazed with the correct alignment, or manipulated in some other fashion. Every hand built bike requires this kind of tweaking, so the builder will at least have a lot of practice. 
I would only go this route if the bike is especially unique in some way. It will require 
repainting the fork and likely cost a lot more than just finding another similar fork on Ebay.