Very nice addition to your collection. You've done a fine job of documenting all of the bulbs in your collection.
I have found that Mr. Clean in hot water does a great job of cleaning ceramic coated bulbs. HOWEVER, you must test to see how permanent the etch is at the top of the bulb first. Some wipe right off while others will not come off with anything. I believe the etch on these GE indicator C-7s is pretty tough because I've cleaned a bunch of mine. The sylvania etch on these comes off fairly easily.