This might be a dumb question but...
Some time back I bought something called a Milton 2-Way razor blade sharpener ("it hones and it strops in one Action"!) from an antique dealer.
It's clearly made for double-edge blades (the top has a V cut into it). But it's all one material (it looks like stone of some sort) and the back is flat.
I was wondering: if a stone is OK to use on DE blades, is there any reason it wouldn't be OK to use on a straight (I'd lap the back first, of course)?
If it helps I can post pictures of the stone, but not until after the weekend.
Cheers.
James.