Victor 1530-6 Professional Grade Heavy Duty Commercial - Printing calculator - VFD - 10 digits - AC adapter - gray
This calculator is so old that they were still experimenting with how the digits should be displayed.. And yes, that is actually how the zero looks. : r/interestingasfuck
Retro calculator with VFD display from PulsarLabs on Tindie
Peter's z80.eu site blog - New toy: Texas Instruments LED/VFD Display Calculators (1972 - 1980)