Hi Keith
As I suggested in an e-mail, you can't really do very much to improve the resolution of an image that you've been sent as a scan (of possible a scan).
The only thing is to ask the person who has the original photo if they can scan the photo again at 300-600 dpi with no compress - if possible as a tiff or png image. you can then resize, etc. and save as a jpg, etc.
Gadget
Think our posts crossed, Keith.