Kelvin Fine China

I bought 4 pieces of Kelvin Fine China from a thrift store. These pieces are unique in shape and I assume they are ashtrays. The weight of each piece is different 1.8 oz, 2.0 oz, 1.7 oz, 2.3 oz. Each of them are approx. 4"x2.5". On the bottom of each piece there is the markings of a crown colored in a purple tone and gold. There is a banner under the crown that is brownish orange and blue stripped it displays the name Kelvin in cursive the banners on first appearance look the same but there is slight differences. On one of the banners the v in Kelvin touches the bottom of the banner the rest do not. Each of the K's in the name also show some differnces. Under the banner fine china is printed and under that the following is printed X-382. Also the bottom of each is depressed slightly in, each of them has various depression depths and angles.

I have searched the internet and numerous websites with no luck of finding anything close to these pieces. I would love to know the history of these pieces. Thank you