Hi - I don't know if specific numbers of Icemen made are likely to be available but try here:
http://www.ibanezcollectors.com/forum/index.php?www
The Vintage & Custom Electrics board will be your best bet.
You might also like this site, might be useful for info as well as Iceman-porn:
http://vintageibanez.tripod.com/main.html
Your serial number, K777541 tells us your guitar was the7541st made in October 1977, the letter K representing the 10th month. The number's the total factory output, not just that model.
Your guitar was built by Fujigen Gakki, the Iceman model appears to be a Fujigen factory design, as they were also sold under the Greco brand. Greco & Ibanez weren't connected apart from using the same factory, and therefore some models being the same.
Jon.