Maybe someone who has made a set of instaaltion disks from those images nore recently than me will remember better, as it has been years in my case, but I would expect to be able to boot from the 'Install Me First' disk/ Disk 1/ whatever it's called and do the install from floppy.

Did you make the floppies just by dragging the files onto the disks, or from the disk images using the Apple program Disk Copy? The latter is what I would expect to have to do. Your 7200 most likely has it on there, and will make the requisite floppies just fine.