Its not really the cabinet as much as the amplifier transformers and the speaker. this is where much of the weight comes from.
As separate loads the amp and cab is not to bad, since they are connected as a combo then you have no choice.
and yes tube combos with large ceramic drivers thrown in are very heavy.
newest way to lighten things is to use 1/2 plywood instead of 3/4 and brace the heck out of it.
but if you want it rehoused as a combo again a lighter housing wont really change the weight much. because no matter what your stuck with heavy transformers and speakers.
neo speakers could shave 10 to 15 pounds.
that is about it, i would not want lighter plywood being used in a combo because it supports the weight of the head as well.
maybe hit the gym, your 18 and could bulk up pretty quick, chicks dig it too
otherwise rehouse as a head and seperate cabinet then lighter wood could used for the cab only, again the very desired EV speakers it comes with are very desired and.....heavy. lighter wood wont change that much.