http://www.rockstomper.com/catalog/pieces/hinge.htm
that is the hinge i bought for my carrier & when i told the machine shop guy that did the fab work for me what i paid for it he said he could have built me one like it in a couple of hours & would've only had about 25 bux in it, instead of the 54 i had paid..
not to mention in order for our design to work we had to dayum near cut the axle housing part in half & cut off about 3" of the spindle shaft, i started to send the left-over back to Rock stomper & ask for a refund of the % we hadn't used..
I'm not knocking RS they supply the market w/ a good product that is hella stout, but i'm just sayin you may wanna find a small machine shop to manufacture something for yer needs that be equal in stature but easier on the pocket..
as for a Latch we (the machinist & myself) built a bolt assembly similar to a "Bolt Action Rifle" assembly..
its basically a 5/8" dia. pin which slides inside a piece of round tubing that has a slot reamed along its length which alows for a lever the engage the carrier arm which has a matching 5/8" hole when it swing to the closed position & stops & the plate where the before described latch bolt assembly is affixed to a bracket..
if yer intested i can pm you some more details..
later..
Lane