A.C. Gilbert light sets

[Nick D.]

How collectable are they? How common/uncommon? I know a good bit about their other products, which are very collectable but I have no clue about their light sets. I've had a 15 light string that takes C-9 bulbs and just today, I found another 15 light string that takes the same size bulbs. They aren't very different from Clemo Co. or Glo-Lite sets, they just have the typical green/red braided wire and black sockets.

Thoughts? Here is the set I bought today (in a grab bag with other old lights)

[Nick D.]

One more question... I know this might be impossible to answer, but what kind of bulbs were originally included in the set? When I bought them, both sets had a number of inside-painted, brass based lamps simply stamped with 120V.JAPAN, appearing exactly the way it is typed...

[Yulelights76]

Regarding your Gilbert C-9 set.
First , I hate to say it, but the set in the photo isn't worth much. The original box is missing, there are no bulbs, and I see the steel clips on the sockets are rusted. This indicates the set was used outdoors and exposed to weathering. If you found a set that was only used indoors, or came from a dry climate, you'd have something worth more! Check the ebay auctions if you want to get a value for your set.
These bakelite Christmas Light sets were popular in the 1950s but once G.E. and others introduced the all green sets, they fell out of favor.
Regarding the correct bulbs to use in the set the Westinghouse C-9 bulbs in the "sentry tower" carton are a good choice. The Japanese inside frost bulbs were used on NOMA and Paramount sets. These bulbs have a dry powder coating on the inside of the bulb.
Another choice is the G.E. D14 ceramic bulbs, also the rippled flame bulbs, although they are hard to find.These bulbs all date to the era when the set was made and I have them on my website check it for reference.
BTW aluminum bases on christmas light bulbs were introduced in the late 1950s prior to this the metal was expensive to refine.
Update 12/15/08
One of my gilbert sets is marked with patent #2,636,069. Found patent on Google and it shows the inventor as Charles E. Gilbert. 
See patent  at http://www.google.com/patents?id=sYtbAAAAEBAJ&dq=2636069
Update 12/29/08
Found more information in a Consumer Product Safety Commision advisory. The Gilbert sets were made by Gilbert Manufacturing Co. of Long Island City, N.Y. As of November 1994 they were still in business. The sets appear to be  quite common as I found many for sale on ebay.
This information is from the advisory.
" Gilbert has manufactured more than 40 million light sets with the fuseholder sold nationally by a variety of major and own label distributors including, NOMA International Inc., Beacon Electric, General Electric Co., Leco Electric, Lidco Co., Markee Products, J. Hofert Co., R.C. Co., and Plastic Assembly Corp. The name of the distributor and in some cases the Gilbert name are printed on the carton of the UL-listed light sets that currently retail for up to $8.99 at retail stores such as Wal-Mart Stores Inc. and Kmart Corp. and other discount, chain, department, and specialty stores. "
I hope this helps.