Grade II BSS's were definately not Sidelocks.
Grade II's were tarted up Boxlocks with cartoonish engraving but much nicer wood.
Sidelocks were Sidelocks
Here is an outstanding article, read all about it!
http://doublegunshop.com/james_flynn_bss_sidelock_article_050104.htmHere is my 20 gauge BSS Sidelock, far left.
I adjusted the downpitch and had Les Pittman fit a beautiful leather covered pad(used the Browning Sporter pad as a base).

Virginian,
Browning did not make any 12 gauge BSS Sporters with 30" barrels and Art Isaacson didn't alledgedly do my barrels, he in fact did my barrels.http://artsgunshop.com/
Art Isaacson is widely known for excellent work, and for expertise with Brownings.
Jay
+1
That 12 and "matching" 20 sure look nice together. Sure you want to break up that couple?
SRH
Stan, you are the man,
I withdrew my offer to sell. A guy would be crazy to loose such a gun!
Thanks,
Bob