Who is/are Royalage?

Burma First Day Covers collectors may aware the term 'Royalage'.  The 1940 stamp centenary FDC prepared by Royalage - Rangoon is frequently seen in the market.  One of the example in my collection is addressed to Royalage, (Stamp Department), 218-37th St., Rangoon.

1940 Postage Stamp centenary FDC prepared by Royalage

But based on that cover, the identity of Royalage cannot be proved yet.  Richard recorded the Royalage as as Dealer. A firm trading at 218, 37th St., Rangoon, incorporating a “Stamp Dept.” that produced first day covers for the 1940 stamp centenary and the one pie stamp" in his book Who Was Who in Burma Philately.  The FDC prepared by Royalage for one pie stamp and comment from Steven Zwillinger in his exhibit is displayed below for your viewing.

<from Steven Zwillinger's exhibit>

So, who is/are the Royalage? The puzzle of the royalage is solved when I discovered earliest FDC prepared by Royalage.  Royalage also prepared FDC for 1938 KGVI definitive issue.  But, no pictorial cachet was created and simple pen writing marks said First Day Cover.  The rubber stamp impression identifies Royalage as bankers and traders.  So, it can be confirmed that Royalage is a group of bankers and traders.  They have their own stamp department, which may be helping them in posting of mail, and philatelic service for hobbyist.

Earliest cover with the word 'Royalage'

The cover is addressed to Mr Shamo Jamwa, C/O Rangoon Stamp Co., 138-30th Street, Rangoon.