One travel advisor recommended packing duct tape for luggage emergencies.
I never leave home without it. I told a friend a couple of years ago to take some. She thought I was crazy but she took some. On day two of her trip to Germany, she tore her down jacket. Guess what she used to fix it?
While there is no "standard" for international bags, most bags measuring 55 x 35 x 23 cm should be okay although some airlines only allow 20 cm instead of 23.
I hate to say it but I think you are going to have a very hard time finding a replacement handle.
That's one of the reasons I stick to bags made by major manufacturers. Recently, I broke a wheel on my bag. (It had nothing to do with cobblestones.) Somehow, one of the wheels got caught on a train luggage rack. I was in a rush and pulled hard. The bag came loose and I was on my way. It wheeled fine. Each wheel was a double wheel. When I got to my hotel that night, I noticed that one half of one wheel was missing. I emailed Samsonite and they sent me a new wheel housing. With just a screwdriver, and in less than ffive minutes, I was able to remove the old housing and put on the new one. Good as new. I learned Samsonite has a webpage just for ordering spare parts. By the way, they sent me a new wheel at no cost even though it had been over a year since I purchased the bag.