Perhaps samples?

you can just use one overhead- is not that uncommon-

My question is, is there any way short of re-tracking the drums to reconstruct a right OH track?

No. You can't recreate sound and/or the same performance of what you didn't record. You can try to process and manipulate the two tracks into something useable. This is where your real creativity, resourcefulness and engineering skill come into play. In the end it may all be for not and you may just have to use the single overhead track and you may not even need that...

re-track the drums...simple and effective.

I've tracked drums before with just one overhead and gotten decent results- use what tracks you got, get a good balance with them and you'll be fine...

If you, by any chance, need to reconstruct the track because you didn't mic the toms separately you could try a bit of eq - find the fundamental frequency of all the toms and "pan" them with a stereo eq, (increase the "floor tom" by boosting the appropriate frequency ever so slightly in the right/left/whicheveryoulike channel) pretty broad q. As long as you don't overdo it it can sound pretty convincing.

Also try a little bit of "phase separation" (don't know the proper term here - I'm referring to the likes of Logic's "Stereo Spread" and the equivalent Waves-plugin) on a highpass filtered copy of the track - it can make the cymbals sound a little more alive.

Here are some tricks you might find handy.

I am assuming you are beefing about this because due to the mic placement you may not hear everything like you think you should. If this is your problem, then you could copy the track and use some mild eq curves to enhance what's missing, and then either apply a very, very, short delay to one of the tracks, or shift one of the tracks a few subframes at a time until you have a wider stereo field. If you do this be sure to monitor your mix in mono frequently to ensure you aren't losing anything due to phase cancellation.

If you can hear everything well, and just want a wider stereo image, you can do the same as mentioned above, but without the eq, OR you can simply put your mono overhead into a stereo reverb or chorus or both. If you do, however be subtle, and if you can return your fx through a rail so you have good control over freq's to keep it clean.

Good luck.