BCRider

If the bearings are running fine with no signs of grittiness or sticky parts in their action then they don't need replacing. Just clean and relube them and they should be good for many a year to come.

Although replacing the balls themselves is a pretty cheap option and not a bad idea. As wrk101 mentions the grease does dry out after a number of years and stops working. If no one redid the grease at any time in the life of your bike then it is well past the "best before" date and really needs to be stripped down, cleaned and re-greased as part of your project. This goes for both wheels, the steering headset bearings and the bottom bracket bearings.

Along with all the other tire suggestions I'll add Continental Super Sports to the list. A superb tire for quite cheap. But whatever you select you'll want to go with one that has a fairly thin and supple sidewall. In my experience this single factor on its own has proven to be a huge factor in how efficiently a tire rolls and maintains speed with the least effort.

I had an old Motobecane from that same era for about a year. Don't recall the actual model since it was quite a while ago. I don't recall what sort of rims it had but it was light mettalic blue with some navy stripes so it may have been the same model. I put on some old 7 speed 700c wheels and commuted with it for a while. It was a really delightful bike but at the time 9 bikes was a few too many and in one of my rare fleet purges I sold it off. Based on my experience with mine I'd give the bike a chance to impress you before you decide to part with it. And steel rims won't let the frame really show you what it is truly capable of. If you find that you like the fit don't be afraid to shop for an older decent quality wheelset that will fit the frame somewhere down the road as an upgrade.

cny-bikeman

Don't get too excited. I don't see where I or anyone else said you have to replace the BB. I would recommend AGAINST overhauling the bearings if there's no apparent problem, unless you are willing to take the chance on extra expense or willing to salvage parts from other bikes. My advice would be different if you had overhauled a bike before. Ride it till it drops.

songcycle

Hey, thanks for the tip about that threadless BB, Binxsy! Going to look at a '76 Grand Jubilee this week (sentimental value -- had one in high school), and it's good to know that the BB can be fairly easily replaced.