the 1.7.10 and the 1.7.10 download link on your website downloads a version for 1.8.9, nor can i find a CoroUtil Download link for 1.7.10 on your site

Yeah its kinda screwy for now, hoping to have it fixed soon, in the meantime you can get it from http://minecraft.curseforge.com/members/Corosus/projects

will backport version updates 1.8.9 or does not make sense?

Not sure what you mean, either way I fixed the old download links issue by manually specifying the latest build version for MC versions.