I say sell them both. I like to shoot 135 film, but to me, it's just not a serious format. It's a fun format, like 110. It's looks cool on a shelf and is fun to take out an mess around with, but if you're going to be doing serious work, I'd rather use my one of my large formats or digital cameras. The level of quality just isn't high enough to justify the cost of keeping a collector's cameras like either of those. If you're like me and you ever nail an amazing shot on one, you'll always wish you had done it on a higher resolution camera.
Of course, those are just my opinions. You are free to form your own. 135 can certainly be a serious format to someone else, and I won't judge them for it. There are no rules in art that aren't worth breaking. But to me, those two cameras you have there are more collector's items than serious tools, and I don't like having a ton of money invested in collector's items. But if they're serious tools for you, then clearly that's different. Or if you're a serious collector, then maybe the investment is the purpose of their existence in your collection. In the end, you just have to ask yourself what would you rather have in 5-10 years: Those cameras, or whatever you'd buy with the money that you got from selling those cameras. Our opinions don't really matter compared to your own.