Interesting problem alright.
I've only seen two Gooses with Widgeon style windshields, 1084 and 1160 (N86640).
Changing floats isn't unusual, but going from a short step to a long step is kind of rare since the step was originally found to be too long.
At some point in the 60s and 70s 1084 was operated by Bahamasair, then in the early 70s by Out Island Airways.
It was rebuilt by Pan-Air in the early 70's and crashed short of the runway at Miami on the return delivery flight.
The wreck was sent back to Pan-Air and rebuilt again, then sent back to Bahamasair.
Back then had a modified exhaust, the short step and fixed floats, can't tell for certain about the windshield, but looking at the profile shots, they seem to have a curve going to the center post rather than a flat line.
By the time Chernoff shot it, it certainly had the new windshield, standard exhausts and Pan-Air floats.
The most recent photos it's back to fixed floats, a long step and standard windshield.
1084
1160 as N86640 when it was being operated by Kenmore Seaplane Svc.
(from a cig. ad)
I'm pretty sure it's the same airplane, but there is room for doubt.