Isotemp OCXO131-100
"Eurocase" OCXO

There are currently (November, 2016) a bunch of small Isotemp OCXOs available on eBay for very reasonable prices. These are in the small (about 1x1.5 inch) "Eurocase" footprint. Here are test results for one of them.

A couple of things to note:

This not a bad little oscillator at all (click on the image for full size):