I have noticed many times that a replacement scalpel blade is preferred over a razor blade on this forum. Why is this?
That's probably because scapel blades are easier to obtain. Single edge razor blades are something of a speciality item. There are also space and volume considerations.
Having said that: scalpel blades can be easily attached to a bit of whatever to make a small, usable knife.
One other option worth considering is the Derma-Shave razor. They also come as a small hacksaw blade. Slightly large than a scaple blade but much better.
http://www.donrearic.com/airman.htmThey are still made and obtainable on E-Bay.