Hey Mandalorian, I'm the maker of the blades in question. First I'd like to say that any improvements or ideas are welcome. Second, I know they aren't 100% screen accurate from any one of the pred movies I purposefully made them not to be. They are in fact derived from someones resin design that was meant to more or less cover any pred costume. (which by the way I have their permission to use).
That said I am also willing to work on custom pieces and can usually make anything somebody wants, given the time and money to do so.
On a side note the slots are for mounting at the request of a client who wanted to do it that way. The rear seciton of the blade is also left soft so holes can be drilled too. I try to make things as versatile and functional as possible.