It would be up to the fire marshall in your state/county if sight glasses would be approved, maybe have to be weights and measures approved too.
Faces have to show price, older ones only go as far as 99.9/10 and would need the extra price window.....and most computers that would be legal would be 4 wheel bank instead of 3.
Then there might be mandatory leak detection....a containment barrier for the tank, monitering wells, and all kinds of stuff I am not aware of since I have not been in the service field for yrs.
Above ground tanks would not require all that cr*p. Then the air eliminator would not need to be used either.
This pump has a newer type computer in it and uses a 2 part face system.
A smaller face behind the big white surround, this would be a way to overcome the face delima for a pump that would have taken a crankback. You would have to have a 4 price wheel face plate though.

A #300 Tokheim could be less costly to set up...it uses bottom mounts for the computer too.
You will pay near $500.00+ for a NEW 9.99 9/10 computer from Veeder Root....I have seen them on ebay...that is WITHOUT the electronic reset, pulsers for your readout equipment, ect.