I had asked about this malt some time ago on another site and got no feedback. I searched the web and found no info either, Rahr has almost no data on their individual products. I suppose they are selling mostly to breweries and they deal with these guys directly. In any case, I had purchased a sack of this stuff and gave it a whirl yesterday in a Belgian pale ale. On a hunch I assumed the "Old World" meant it might be less well-modified than a normal malt, so I did a protein rest and then stepped up and did a long, 90min sacch rest at 150F. I got usual efficiency with this program so I was satisfied that I'd at least gotten good conversion.
In any case I was still curious so this morning I called Rahr and they sent me to Brewers Supply Group and I eventually talked with someone who gave me the scoop. This malt is made from Moravian barley and is less well modified as I suspected. Basically its the domestic equivalent of a Bohemian pils. I'm actually glad I made the selection, since I do enjoy a German lager.