After reading the specs, it is quite clear these are replacements for the collapse rescue units. The compartmentation specs specifically mention quantities of wood to be carried in the rear, similar to the current collapse units, and the paint/decal specs specifically mention "Collapse Rescue" lettering with the company number. Yes, the six-seat cab and boat motor mount are changes from the old version of the collapse units, but it is fairly normal for apparatus to evolve with different specs through different generations. As far as why they're ordering 7 and not 5, I have no idea.