About a year ago a purchased a Rokinon 14mm f2.8 lens for Canon. The lens has a built in petal lens hood and a large bulbous lens. Because of the lens design, it required a non-standard lens cap, which came with the lens. The lens cap is very deep, looking somewhere between a small cup and a bowl. It fits entirely over the hood and snaps into place behind the front element.
Unfortunately, my camera bag took a tumble from the top shelf of a bus when the bus rounded a corner with surprising speed. Luckily (and surprisingly) the lens cap was the only casualty. As the lens cap is not standard, I contacted the manufacturer both at their US point of contact and their Korean contact (Samyang - I live in Korea and the lenses are manufactured here, so it's a natural contact). The US contact responded asking me to fill out a form, but hasn't responded since then. The Korean contact never replied at all. There's also no information related to obtaining parts for these lenses, so it seems like I'm out of luck in obtaining a replacement.
The manufacturer doesn't seem willing to sell parts. The cap is custom, so there doesn't seem to be any other source. The lens is bulbous and has a built in hood, so I can't attach a filter to protect the lens.
I don't want to risk damaging the lens by carrying it without some protection. I also don't want it to sit on my shelf unused. What can I do to provide some protection for this lens?