In reply to G7MLO:
I bought a black fabric “man bag” “Pierre Cardin” branded (!) from an airport for my FT857. The top is zipped and then clipped and it has a short carrying handle on the back. These seem to be available for £10-£20 depending if you buy them in Bangkok or at Heathrow. They have a removable shoulder strap, extra pockets and are a perfect fit for the FT857. The rig is of course removed for operation but placing it on top of the bag prevents damage to the rig case. I would think you will find a similar one in one of the shops that just sells bags and cases, which you see in town and shopping centres.
Good Luck - the FT-857 is a great rig and very underated I feel.
PS The rig with the mike attached all fit inside the case - it’s perfect, so good hunting I hope you find one. I don’t think you want to carry an aluminium case up a summit personally. This soft case is 11" X 8" X 3.5".