Spital in Regensburg has a wonderful beer garden on the Danube. Really good food, too. Kneitinger has a lovely beerhall, too. Don't know if either do tours, but they're well worth a visit.
Schneider isn't a monastic brewery. I don't think it ever was. They do a pretty decent tour. Though they...
That would be from London and Country brewer, then. Pretty sure the recipe for Porter (though it isn't called that in the book) is 100% diastatic brown malt. I can understand you might want to try and create something similar with modern malts. But black malt is totally inappropriate.
That's not a recipe from 1744. At that time, Porter was rewed from 100% brown malt. Black malt wasn't invented until 1817.
I'm not saying it's a bad recipe, just not anything like one from 1744.
For Obadiah Poundage we got Andrea at Valley Malt to make brown malt the scary way. That is, using hardwood to boost the temperature right at the end of kilning. The grains that resulted were very inconsistent, varying from pretty much pale malt right through to scorched black. It looked like...
After WW I almost no Old Ales were really aged. There were odd examples, but most were just strong and usually dark. You get dark fruit flavours. But they'd be coming from the sugar, most notably, No. 3 invert.
I see they've nicked quite a few of my recipes on that site. If you're interested in more, direct from the source, I've just published a book with 553 historic recipes from WW II.
Blitzkrieg! Vol. 2