I have a K model frame for sale on eBay right now. It is perfect and stamped "5L" -- December, 1955.
Plenty of photos, take a look:
or refer to eBay item# 110256899352
I'd really like to see this go to someone that's restoring a correct year K model. The frame looks like it just came from the factory!
You can give me an offer outside eBay and if I like it I'll check the eBay rules about ending an auction. Use email address below. 4 days left in the auction.