Removing floor from raised rear bath

[painterfam]

I have a '59 Overlander with a rather interesting feature: the rear bath is raised 2". It came from the factory that way.
My conundrum is, I'm not sure how to put the floor back in, without either cutting the floor (prior to putting it back in place), or taking the shell off. Let's assume taking the shell off is not an option.
Has anyone encountered this unique feature? I've attached a photo - there is a rib that meets the end of the floor panel. (never mind the pool noodles )
Thanks! Rachael

[painterfam]