"If it is an Erfurt proof on the front of the triggerguard does that mean it was a force match?"
The Erfurt proof stamp in this position has no documented meaning.
From the photographs I see nothing to indicate the frame-to-receiver being a force match.
"I think the rights side of the slide is army proofed to dmw."
You are correct in your identification of the power-proof stamp belonging to the inspectors at the DWM factory.
"...I'm showing my ignorance here is 'BKIW guns assembled in 1929' ?? Could you tell me what this is or means?"
Don't worry about not having knowledge, we all started there. In 1922 the DWM company began to do business under the name Berlin-Karlsruher Industrie-Werke (BKIW). Although the DWM monogram continued to appear on the toggle link, P-08s continued to be manufactured by BKIW until the production equipment was transferred to the Mauser factory in 1930.
"Why is it export marked but chambered for 9mm?"
The variations of Lugers made available between the wars, particularly just after WWI, are nearly infinite. Conventional wisdom has it that Germany was so starved for currency that they put together anything they could into functioning pistols, export-marked them, and shipped them out (click
this link for another very strange example). The 3 3/4-in, .30 cal. requirement was a result of the Treaty of Versailles, and applied to guns sold within Germany. These were exported too, but as newly-manufactured pieces.
"Oh one more thing, did they dip blue these when made, as the reblue look quite old."
A differentiation needs to be made between salt-blue, a chemical-immersion bluing process used for Mauser-produced P-08 beginning 1937; and dip-blue, a black coating process used by the East Germans and Russians on Lugers captured at the end of WWII (the original finish on pre-1937 Lugers is rust blue). From your photos it is easiest to suspect that this Luger has been salt-blued--the interior of the pistol is blue, not polished--indicating that it was probably re-blued after it left Germany.
"Last thing. The grips are quite worn but are unnumbered on back with some type of waffenampt stamp on each one. An eagle with 3 numbers very small."
Photos of these grip stamps will prove very interesting, as they may provide a solid clue as to their origin and possibly help fix your Luger in time.
-Dwight