The answer partly depends on whether there is a Barrettscv Significant Other who might object to the accumulation of bicycles. If so, you have to decide if it's worth the blowback. If not, Bob's yer uncle.

You can start by making the Trek as redundant as possible. Same tires/saddle/bars/gearing, similar hardware. Are the frames different enough that the ride feels different? Educational, and fun. Then, is there something the Trek can do that the Nova Special can't? Fits wider tires, fenders/racks, longer wheelbase, etc? Make it different enough that it's no longer redundant. Now the Nova Special is the good weather, smooth road retro ride, while the Trek is the crappier weather/crappier road retro ride. Or the lower-gear ride for hillier rides, or it's got the rear rack/big saddlebag so you can stash more stuff, or vice versa, or...whatever fits your needs.