Wow, hehe. Personally it's really hard to say as I've never dealt with numbers as low as 50 ;). But for my Worm Inn, I put a lot of bedding on the bottom to basically seal it until the VC builds up and forms a plug at the bottom.

With so few worms it's more of how much of the compost do you want to add as opposed to the ratio. You can go wrong with bedding so there's no thing as too much.

So I'd put lots at the bottom as a plug, Just cardboard to start, then you can put cardboard in with a little bit of compost and build up some layers. I find that useful (I use coffee) as anything between two pieces of cardboard stops them compacting and forming thick slabs. I think I almost quarter filled mine with cardboard when starting. Then you can add your compost depending on how well processed it is (ie.is it going to heat, or turn to ooze and dribble out the bottom...). Might want to break it up into servings and keep some outside until needed (break it up now before it freezes solid).

Then put another inch of cardboard bedding on top. Move that aside as you add more of your compost. It's a second home, helps hold moisture and shades the top layer of food being eaten if you've a mesh top.

I find the cloth systems pretty indestructable, but I try not to fall into a habit of trying to destory them ;). But with plenty of bedding and that type of system, hard to go wrong. The tricky thing to start is keeping it moist when you don't have that much VC to retain water. Just cardboard with that much airflow can dry out pretty quickly, but overwatering without VC to hold it can end up just draining out the bottom.