plywood tanks are awesome! my friend has a 500 gallon plywood tank and the thing is huge!
one concern that comes up is the glass, do you think the 55 gallon glass panels are enough to hold the extra weight?......also if ur 55 gallon was a standard 55 shouldn't all the panels be tempered?
w/ those dimensions i get a minimum thickness of 0.31" @ safety factor 2 for non-tempered and .10" @ safety factor 2 for tempered glass.
the best democracy money can buy