There were actually several levels of Signet clarinets. The Specials, I've been told, are the best. I think that's what my wife has ....
Anyhow, you might want to do some searches here regarding bore oil and oiling in general. I, myself, oiled my first clarinet I got when I was, oh, eight or nine, and never did it again on any of the dozen-ish clarinets I had since then.
Yes, I'm the Artist Formerly Known as Saxpics.
Note: I'll only be around occasionally until December 2015.
If you need me or just want to chat, e-mail me @ thesaxinfo-at-gmail.com.