Tough to beat "good luck" or diligent searching.
But seriously, I don't recall anyone here saying one could buy what Tom wrote in his post:
"I have never seen a $900 artillery or a $500 alphabet that is in good shootable shape. "
And one just cannot tell if a luger is in "good shootable shape" from a picture; people sell guns "cheap" for a reason- the reason often being that they don't work "exactly right". JMHO.
If you want a luger to shoot, better buy one from a guy that has shot it and will "guarantee" it to shoot. The only place to get one of those is on this or the other luger board. Again JMHO