Both the brown and 1109 are normal. Each tamer boss has a 1 in 10 chance of dropping a mask so with two of them in the instance its 1 in 5. Either color mask has the same odds of dropping. I was wondering (believe) if one of the bosses has a 1109 and the other has a brown mask which might explain the hue difference. I have brown and it's valued a mil or two less than 1109.
I'm not familiar with the drops on these as I just purchased the mask myself. I assume Artex is right until stated otherwise
And maybe control white wryms a little better. They can be stubborn. Not sure how effective +5 taming would help with that.