Update on this...
This brew's SG bottomed out at 1.014 in the secondary, from 1.018. Beer tastes great, which is a relief as I made 12GAL of the stuff.
This batch was an attempt at a Picaroons best bitter clone, and I must say, I think I'm bang on with the grain and hop quantities. I'll have to have a second taste when it's finished carbonating, but the initial room temperature taste really closely resembles picaroons. Again, I'll need a second taste, or a side by side comparison to confirm.
If it is very close, then it makes me wonder if picaroons doesn't mix ringwood with other yeast to get their signature taste.
I bottled 10L so I'll have some to bring to a meeting to share.