Thanks for the input!!
My solution: I got out my handy dandy jig saw & cut a 4 in chunk out of the top & was then able to maneuver the box out from under the seating area. Given how NASTY this was inside, I would not have ever felt comfortable using anything that was stored inside of it -- germ phobic & having had dysentery while stationed over seas, I'm a little snake/bug bitten & twice shy of such stuff (there's a country song in that last sentence, I'm sure!).
Love the idea of the inspection plate (thank you Donna) -- I will install one of these on my new tank. I've ordered a 6 gallon with dimensions of 16x12x8 for a couple of reasons:
1) The 12 Gallon was hogging up about 1/2 of the entire back section storage area. The water tank was sitting an an odd angle that was eating up side & back compartment space that I really need (3 of us traveling are girls & while the Army taught me how to travel really light
, my 8 & 9 yr old princesses have yet to get the memo on it.).
The new tank will fit nicely between the wheel well & the FG wall, snugged up right next to the sink. Less of a pull on the system too when I have to manually pump as the tubing/line to the sink is now only 24" long vs. about 44".
Now I have almost all the storage under the driver's side bench & all the storage under the back bench area -- yea!
2) Most of our camping will be pretty local & probably at camp grounds. In Austin, full hookups seem to be the norm rather than the exception & thus, no need for a whole lot of on board h2o storage. If I was boon docking, I would probably take an extra water supply or rig up a piggy backed system of 2 x 6 gallon storage tanks in tandem.
A big fat Ozarka bottle that could be poured through the top mounted inspection plate on the new 6 gallon tank would be an alternative to rigging up something more complicated (a bunch cheaper too I suspect..).
I've done some nice cleanup on my little Burro -- New floors (with a twist -- I'll be posting photos), New headliner with marine carpet (not terribly happy about this job but it's clean & (mostly) neat so my OCD stimulated re-do will have to wait until other projects are done. Stripped, sanded, painted & distressed the doors & replaced hardware. Mounted kitchen organizing hardware on back splash area of kitch (love a well planned assault on the local Ikea store!) & am building shelving in the closet area (totally stealing the idea of using PVC pipe & shelves from another poster on this forum). Lots of hard cleaning & liberal use of elbow grease & my efforts are staring to shine -- I love making something my own with a little bit of sweat equity!
Hardly an original idea to be found in my little rig but, hey, copy-catting is really the nicest form of a compliment, right?
Tomorrow, the new faucet hardware should arrive from Amazon so that is next. The new h2o tank gets here over spring break so that is on the list too. Vintage/retro fabric for new curtains came today so, yep, that's on the list too.
All this is driving the husband bat **** crazy, lol. He's a $150K big fat diesel pusher kinda guy -- the kind that wants to go "camping" without really, well, going camping. The idea of a 30 year old 13' egg on wheels that needs work is perfectly baffling to him.
Thanks for all the help & speedy replies to my queries -- you folks are the BEST!!!