I'll start out by saying I'm totally new to bikes as an adult so forgive me for my lack of knowledge. I've recently become interested in the idea of bike commuting to work as I currently live in southern California where the weather is pretty favorable.
In my research I decided I really liked the idea and looks of a vintage steel road bike. In my searches I came across a '73 Raleigh "Grand Sport" in great all original condition. The guy had it listed as a 58cm which is at the top limit of what I had figured to be my ideal size (I'm 5'11" and after multiple online fitting programs determined my size is 56 to 58cm.) When I went to see the bike I noticed it felt sort of awkward but I assumed it was due to the fact that I had never been on a road bike in my life so I decided to go for it. Once I got home I double checked the size and measuring from the center of the top tube to the center of the BB it measures 61cm. So my question is am I not understanding vintage bike measurements or did I buy a bike way to big for me. I'm guessing it's the latter so I guess my real question is if I could make the bike work by switching the 27" wheels to 700c and slamming the seat or should I just sell it and keep looking? Thanks.