After doing research on the issue, it appears that the economical approach was a Trimble 65256 OCXO ($16) as it is well respected, has low phase noise, is sine wave and is SC cut.
Morion 89A was a close second. The Epson Toyocom TCO- 6920, while interesting, I can't find any data on it and it's signal was under 0 dBm.
As a low risk approach I ordered a $16 Trimble OcXO, 12V, 10Mhz Sine, o - 7dBm output unit that didn't look banged up and the current draw isn't unreasonable.
Once all is well I'll make a low noise linear PSU and an isolated 50 ohm distribution amp and feed the various instruments.
As a useful spin off, I'll do a divide by 2 reference for my DC505A counter to replace its tank circuit. I believe it's a 5MHz ref.