So I've made a couple batches so far, both were good (drinkable at least).
First was
9# Briess 2-Row Brewers Malt, Lovibond 1.8
12oz Weyermann Carafa II (Dehusked), Lovibond 375-488
4oz Chocolate Malt, Lovibond 350
This one was VERY dark. Not a 'clone'. Also had a phenolic infection (per an expert taste test). I suspect that it might have been due to suck-back when I chilled the wort in the primary with the blow-off tube installed... Don't do that. (This was my first batch ever).
My 2nd attempt was:
9.5# Briess 2-Row Brewers Malt, Lovibond 1.8
4oz Weyermann Carafa II (Dehusked), Lovibond 375-488
4oz Chocolate Malt, Lovibond 350
This one I tasted along side some real Widowmaker. Mine was a little drier, and less sweetness. I suspect because I wasn't matching the 94% light, 2.5% black, 3.5% chocolate (per the sheet at the bar in Houghton) So my next batch I will try to bump UP the chocolate a little.
My next attempt will be:
9.25# Briess 2-Row Brewers Malt, Lovibond 1.8
4oz Weyermann Carafa II (Dehusked), Lovibond 375-488
8oz Chocolate Malt, Lovibond 350
or perhaps
9.375# Briess 2-Row Brewers Malt, Lovibond 1.8
4oz Weyermann Carafa II (Dehusked), Lovibond 375-488
6oz Chocolate Malt, Lovibond 350
BadDeacon -- Adding coffee, IMO, will make this less like the widowmaker than it already is, and 12 oz is (while not bad tasting) already too much as compared to the real deal.