Some description of the bike would be helpful. Pictures with details of the frame construction and so on will be the best.
The Coast King bikes were built under contract for department stores. I want to say these were sold by Gambles' Department Stores. I'm going to have to look them up. They were built by major manufacturers like Huffy and Murray.
So... what is the tire size?
What is the frame style?
Men's or ladies?
Skinny tires or middleweight or balloon tires?
Fenders? None, painted, chrome, full-length or short?
Rear hub? 1spd, 2-spd, 3spd, 5spd? Something else? Paint on hub? Brand of hub? Shifters?
Seat brand (stamps or tags?) Handlebar style?
Painted graphics, decals, stickers, stripes, other names or tags on frame or forks?
These store brand bikes changed annually and mainly came from American manufacturers in the early 60s through early 70's.
When Huffy took over Monark in 1958, they inherited Monark's supplier agreement with Coast-To-Coast stores to produce some of the Coast King brand bikes. Huffy also inherited the "Bearcat" model name from Monark and used it for some of their Coast King branded bikes like the 1964 model below.