Floated Plate Blocks That Fall Apart

I dont know if its called a plate block or a sheet really?

it was a 10 stamps by 7 stamps block/sheet

I floated it off a box shipment that was sent to me, my inexperience floating something so big the bottom two rows came off and the center perfs started to separate 1/3 of way up...

its a common stamp and 1978, and it was more educational for me to try to do it.
however, now that it is separated what is the correct method of salvage? 4x4 blocks starting from the top left, including any edges with plate/block #'s?

also this particular plate/block switches design on 1/2 so do I save the center in blocks of 4 (2 stamps from each part?)

Like this?
XO
XO

or

XXOO
XXOO

I would divide it into blocks in a way to best preserve the selvage.