I have a number of leftover trinkets from specialization collections, e.g. Riddle of the x, as well as the various karma-bought ones. These can be placed in the MF window, but cannot be placed together, nor be placed with anything else as far as I've seen. It seems unlikely that these would have a specific recipe since they can only be obtained once. Are they just enabled for the MF by mistake or is there some way you can actually forge them?