[Milsurplus] identify this Sickles 4495 kcs. crystal ?

[Hubert Miller]

Ah yes, i overlooked the DC-10 on the crystal holder. I would have noticed it - eventually. Thanks !  I kept looking instead for the photo, but all seemed to be conventional packages. 
When i found this quartz,  i immediately guessed it had to be the crystal used to "crystalfy" the one plug-in tuning unit for the BC-230 / 430, to give it fixed ground - air frequency
instead of VFO. 
This crystal is sealed. I suppose you could drill out the 4 fastener rivets. I will mail this free to someone with a BC-230 or 430 who maybe would care to put a crystal for
say, 3885 inside and modify a coil. Yes, there was an official instruction for this modified coil. I think i sent a copy to Mike Hanz some years back. 
-Hue Miller