Locking stays can usually be had at large hardware stores, or for a greater range of sizes and mechanism types, try the yellows in your area for cabinet makers supplies (just about every large town has one, and every city has a few). Stainless or brass is good, chrome plate is bad; when it begins to corrode (and it will eventually in timber case exposed to air) there is a vapour phase that reacts to damage many types of lense coating, and may damage fluorite elements.
Alternatively, buy some cheap lint free cloth and sew a little tube for each chain, 50%longer than the chain, and slip it around like a sock, then stitch it on to the top and bottom link (if you make it longer than the chain, even if the chain gets free at one end, it can't get out of its sock and cause trouble). Kid leather offcuts from any saddlery or milner, also are good and usually free. (to sew a neet tube, make it inside out to sew the seem then turn it through itself to hide said seem and make it look pro)
Regardig weight: Put a handle on one end and some good quality wheels on the other (or wheels at both ends and ride it like a scooter
Daemon
