That Luan is a very poor clone of Baltic birch, and is a pain to work with as it splinters no matter what you do. I have seen it in 3/4" and it can have about 13 plys but it is crap. Furniture company's will use it for the back panels of cabinets in 1/4". True baltic birch will come in 5'x5'...
I think the EV's are about twice the weight of a celestion. Next week I will put each one on a scale and post the info. Also I have a vertical mesa metal grill cabinet I am tearing into in order to repair a corner joint and do a re tolex. I will take some pictures and post them. I can confirm...
New cabinets are built using 13 ply but the old school metal gril cabinets were cheap 5 ply wood. I think your weight might be the EV's if you have those stuffed in the cabinets :D
A switch sounds like a good start. Also if your able to remove the top cover and let the tube heat escape I think that would work. Just don't spill anything in it while the lid is removed or drop the screwdriver in there!!! :shock: