I am enjoying restoring an old Bridgestone mountain bike type bike to functionality. I found it almost impossible to get the bottom bracket off. The bottom bracket was deteriorated inside and so I decided to go to a more modern cartridge bottom bracket which will fit the English treads of the frame. I measured the shaft and width of the bottom bracket threaded area and ordered the proper size bb. I also couldn't get the 5 speed freewheel off the rusted rim and decided to convert the old bike to a 7 speed which I have an old free hub that I can put on a new rim with a proper 7 speed hub. So basically, I ordered cheap rims and skewers, bottom bracket, cheap 7 speed shifters, and a specially modified back derailer which will fit the frame as it does not have a modern day drop out. I am not completely redoing the frame, but I am eliminating the rust spots and adding some hand painting over the sanded rust spots. The original cranks took a while to clean up, and I don't think they should cause a problem with the back gears, but if they do, I can easily replace the crank with an inexpensive hyperglide type mountain bike crank.
My friend will once again have the bike she so loved in her younger years. I will also purchase a good park tool kit as I realize that I enjoy working on old bikes and my assorted tools just aren't enough to do proper bike work. Regardless, the activity is very enjoyable on these cold cloudy days when I'm not out riding or working at the factory.