I could have sworn they are the same mold between the two...
If they are four to a press or similar, as per other older woodshops, then that could easily account for the slight differences in concave.
Same press but the top board will always be a bit more, the bottom board a bit less.
Most woodshops still have the older presses, which are usually single or at most double stack multi board big solid things, compared to the newer more streamlined presses that have up to eight or so single press molds on the same stack.
I don't know enough about most of the smaller woodshops, but very few have the newer technology, unless they had a huge overhaul or have just started more recently.