The Langley Co. made aluminum aircraft parts during WWII and used that knowledge to make very fine light weight fishing reels from 1948 to 1962 when they were bought by Zebco. Zebco continued to make the 310 and 330 model bait casters and 6 of their spinning reels, which is why they bought them, to get into the spinning market.
Langley’s main selling point was their anti-inertia spool and light weight. They are great reels. They made a ton of 310 reels because they were so popular. The KC is a model marking and there were others, but KC is most common. left hand 310 ,311 & 312. The 310 has the standard 3/4″ anti-inertia spool, while the 311 has a larger 15/16″ one and the 312 is small solid shaft one at about 3/8″. Langleys are great reels to collect. There are many variations 310 A, 510 A, 330, 340, 310 Streamlite, 330 Lurecast, 350 Lakecast, 500 Reelcast, 340 Target (Narrow Spool Tournament Casting Reel); 350 Lakecast; 360 Plugcast (Narrow Spool); 370 Deluxe Lakecast; 380 Castrite.
These are the 500 series reels: 500 Reelcast; 505 Shorty (Narrow Spool); 510 Speedy; 520 Topcast; and 530 Speedcast, 520, 530 in the wrong place. The 530 is Green and the 520 is Red.
Left hand 310; 310; 311; 312; 310A, 350 and a 410 Whitecap, 444 Dyna-Matic, 490, 470, 995s : 995B, 995G, 995R.
Fly reels 166FA, 175FA, 176FA , 185FA , 191-A; 192-A 191-B, 165FA.
List above are a few of the Langley reels.
I like the Langley production reels because of the many different models and designs. They are in most cases an in-expensive reel for any collection. With the box and papers they can sell in the $40.00 to $50.00 dollar range in good condition.
I borrowed some of this information from Fishing Talk. Thank Those for the knowledge and advice. http://www.fishingtalks.com/ if you want to ask a question about a fishing rod or reel this is the site to go to.