George,
I haven't done it, but can tell you that you will have to do some impedance matching to get it to work. Doing away with two elements with any tri-bander will mean the input impedance will go up. Shouldn't really be that difficult, but it'll have to be done.
Would it be worth doing? Just depends on what you have, and what you are expecting. It should be at least 'better' than a fixed dipole, and if the thing has damaged director/reflector elements, what'cha gonna loose?
- 'Doc