Early doors

Does anyone know the origin of the (I think) Yorkshire
phrase

"it's early doors yet"

by which iy is meant "there is plenty of time at present"
thanks for any advice
regards to all

"Ron Atkinson is the inventor of the phrase "early doors" a juxtposition of two previously unrelated words, which has been unquestioningly accepted into the English language. As such he should be cherished."
- Lemon, Apr 24 2001

From what I can gather, everyone has more or less decided he's trying to tell them it's early in the game yet.

Early doors is also cockney rhyming slang for a pair of drawers, as in knickers. Hmmmm...

Here in the US, musicians and club owners will often say "The early door looks good" meaning there's a crowd lined up waiting to pay their cover charge well before the doors are scheduled to open, so chances are good of a heavy turnout and a profitable take at the door.