[78-L] Brilliant and Canadian Brunswick

[Han Enderman]

Sutton-Nauck ARLC say (p28) that the last vertical Br(C) discs were issued in 1920,
with US style labels & jewel point notice.
Br(A) began issuing lateral discs in Jan 1920 (p28).

ODP (= Ty) lists the common US 5000 series, with the bluish-purple label.
Laird (Br dg, from google-books) lists:
5000 - 3129/3426 --- (4/20)
5001 - 3364/3369 --- (7/20)
5002 - 3567/3709 --- (7/20).
I assume that the dates in parentheses are release or advertising dates
(google-books can only be consulted in small fragments here, and I have not tried
to find the explanation).
For mx 3709 ODP gives a June 20 recording date.

I see 2 reasons for the use of the Brilliant label:
- to avoid the same cat.nr for different issues. Canadian verticals were in a 
5000/15000 series, and lateral issues also used the 5000 series, so they changed
the label name to avoid numerical confusion.
- to avoid any confusion between vertical and lateral issues (i.e. from mid 1920 on 
every Br is lateral).
So the remaining vertical stock got paste over labels.
Was there any need to keep some popular verticals in the catalog?
Anything known about vertical Canadian Br catalogs (supplements) or ads?
How complete is the known "list" of issues?

Han Enderman