Alaska Guide Creations....I have 12X50 Razor HDs and I keep my rangefinder in the front pouch..my wind meter on the sleeve on the top flap, my havalon on one of the side pouches, extra rounds and chapstick in the other side pocket, and license and tags in the pocket on the back.
They sell them at the RokSlide store. Been using them since 2009 and still haven't found anything better.
Its nice to be able to drop your pack if needed and still have your license, tags, GPS, and knife with and even a snack bar if your stalk gets away from you. I try to never leave my pack behind regardless, but sometimes it still happens
Ryan Avery has tasks me with doing a review on this since I have 6+ years with one now, hope to have that up before Thanksgiving.
Anyways, here is the link to buying them in the RokSlide store:
http://www.rokslide.com/store/category/23-alaska-guide-creations-bino-harness
I have the size large that isn't carried by RokSlide but a lot more options at the actual website as well your 10X42s would easily fit in the medium (standard) size as well:
http://alaskaguidecreations.com/blog/store/