Burroughs

Burroughs were one of the original manufacturers of Nixie tubes. In fact ‘Nixie’ is a trademark of Burroughs Corp. They bought the company that actually started manufacture of Nixie tubes – Baydu Brothers. Though there are earlier mass-produced cold-cathode numeric display devices made by National Union.

B54370A

The B54370A seems to be a variation of the B5441A - it has a comma in place of one of the decimal points, probably for use in displaying thousands.