Looking for any info on Frank Costin and his wife Katherine (unknown maiden name). Franks DOB was 20 Nov 1873, he was born in England and immigrated sometime between 1887 and 1910. He settled in Idaho and had 3 sons with Katherine.

Some alternate spellings I've seen for them are Costur, Costen, Coston.. Katheryn. Katherine was born in 1888 in Prussia.

If anyone has any info on these two, or can point me in the right direction, that would be much appreciated. I'm hitting a brick wall with these two. Siblings, parents, places of birth.. thanks!