So I recently acquired 74-75 Fender Bassman Ten. It was sitting in the corner last night in front of my snake's cage while his light was still on and I feel like I can see through the grill cloth on the top two speakers when she's backlit. Which brings the question - how in the hell do I get this closed back cab open to check it out? She sounds great - just really curious what's in there if it it isn't 4 32 ohm 10s. Any help would be appreciated! Thanks!