First , that fridge is not that old. it's enegerncy useage is not far off from toadys fridges.

There was a time (late 1980's) the compressor design made a large leap . this was the tipping point from large enegery useage and what we consider normal today.

for example and this is a true story. : i have two fridges

One :is a GE(garage fridge) from the late 70's it uses $21.00 of electric in 30 days

Two: is an Amana(kitchen fridge) from 1993 (still running R12) it uses $9.00 with the ice maker turned off in 30 days.

How much could i save if i replaced the Amana with a new model?

a Dollar or two a month if i am lucky a whole 24 Bucks a year

your examples are going to be even lower you might save a whopping 18 bucks a year or even 13 whole dollars.....wow.