Steve,
It doesn't matter where you're from (I'm from Canada too). The thing to remember is that you weren't allowed to sing sexually explicit lyrics back in the early days of blues. Since many of the songs deal with sex, adultery, cheating, drinking, etc. (big surprise there ay?) there are a lot of expressions alluding to these subjects.
I've heard "dust my broom" used both ways; to leave, or to have sex. "Nation sack" could be a contraction of "donation sack"; a purse in other words. A rider is definitely a sexual partner. A woman with an "Elgin movement" is one that's put together well or well-made might be more appropriate (Elgin is a make of watch).
There was a thread a while back on this subject. If you search the threads you can probably find it.
'Til then don't let your needle get rusty and don't break your winding chain.
Dave T.