Blending Premo & Sculpey III

Hi all!  Due to happy circumstances I have received a large quantity
of Sculpey III (large quantity = at least 150 2 oz. packages).

My preferred brand is Premo.  However, this big pile of Sculpey III
just begs the question:  how well does Sculpey blend with Premo?  I'm
thinking especially about mixing in a bit of colored Sculpey into
Premo translucent, but also in all other color combinations as well?

Does anyone have any recommendations on the best proportions for
mixing these two clays while not sacrificing Premo's superior
durability and ease of use?   Are we talking 50/50?  Or three-quarters
Premo to one-quarter Sculpey?  Or is it an even lower proportion?  
I'm ready to do my own experiments but was wondering if anyone had
experience with it themselves.

I don't want to think that the Sculpey is completely unusable for my
purposes.  I mean...that is a LOT Of clay and I'd hate to waste it! 
So suggestions for its use other than blending it with Premo are more
than welcome!

Thanks for your time!