[78-L] Joe Davis labels

[Han Enderman]

Can someone explain the 4-digit numbering method of the various Joe Davis 
labels (Beacon, Celebrity, Davis, Gennett (New Series), Joe Davis) ?
Davis also has a DA series (based on albums, like Asch does), 
and there is also a 3-digit series (Beacon, Davis), 
but all labels use 4-digit cat.nrs in ca. 15-20 series with irregular numbers.
At first I thought that the last 2 digits formed a continuous series, but I'm not sure 
if this is partially true.
Examples are Joe Davis 7207, 7320-23, 7420-21, 8125-30 (8128 never seen), 
8191, 8250; Celebrity 8125 & 8128 & 8190; Gnt 8126.
It seems that the same nr (when used) is used for the same titles on these labels.

Is there a list of all issues?

Han Enderman