Stepping Question

I'm going to get some British Ale II, about a teaspoon, from the dregs of a number of bottles I brewed about 1 month ago. It was a medium gravity beer (Surly Bitter). Using yeastcalc, I see a 1L starter at first and then a second 1L step gets me about 100B, which should be plenty for my 3 gallon batch. So I'll get the first 1L going, no problem there, but how does the second liter come into play? Do I just pour it in 72 hours from now? Or do I drain? I'll be fermenting at 70F. The 72 hours will get me ready to pitch the completed starter next saturday. In fact, I'm splitting a Lakefront Fixed Gear brew into two batches, one with WLP001, the other with the results of this starter.

Depending how big flask do you have, either way you will add fresh wort on yeast.
You are dealing with really small amount of yeast so your inoculation rate is too small. It shouldn't be a problem if you take good care of sanitation process.
The problem with small inoculation rate is that it will take long time for yeast to create environment that is unfavorable for other microorganisms, so disinfection is crucial.

Your other option is to chill the first starter after high krausen to floc the yeast so they settle. Then decant off the wort. While you prepare the 2L starter, let the yeast gradually warm, you want the temp difference between the yeast and the new starter to be 10F or less. Add the new 2L wort to the yeast. It will take 2-3 days for the 2L starter to finish then chill that to get the yeast to settle again. Decant, warm and add to the batch of freshly made wort. I usually do this final decanting the morning that I am brewing.

So I collected 5-12oz and 2-22-oz bottles (of a one month old Surly Bitter batch) this weekend and have dropped the dregs into 500ml of a 1.040 sterilized starter (2oz DME). I actually spooned a bit of wort into each bottle and shook it. I aerated by shaking the jar (that's the foam in the picture, no fermentation yet). I may very well have a teaspoon of slurry in there, hard to tell. The container is a 1/2 gallon canning jar. I plan to ferment at 72F and add 1L of 1.040 wort in 2 or 3 days at high krausen which, according to yeastcalc, will give me about 90 billion when it's finished off. I will post pics along the way to show the action. I'll do the cold crash at the end of the process, as I don't want to disturb the lifecycle midway. Who knows, I may even dump the starter in its entirety into the batch. I plan on dropping it into a split 7 gallon batch of Lakefront's Fixed Gear amber ale, with WLP001 in the other half.

By the way, yeast is the Wyeast British II, I expect it to show some activity quick. I used about 1/8 teaspoon of yeast nutrient.

At 30 hours, nice krausen, cloudy wort, lock is bubbling. Smells great. I was a bit concerned about the fact that I did not sterilize the yeast energizer, but all seems well.

it's best not to use an airlock for starters - you actually want to introduce as much oxygen as possible

Well I woke this morning at 42 hours after starting the starter and decided to go ahead and cold crash the starter, as the krausen had collapsed. At 52 hours, I've made up a 1.5L (5oz DME) starter and will pitch tonight. I'm surprised at how quickly the first starter completely fermented out, less than 48 hours. I guess that is one benefit of the 1.040 starter OG. I hope to have this 1.5L second starter at high krausen or fermented out by mid day Friday, otherwise I will have to brew on Saturday. Here is the decanted starter waiting for the 1.5L 2nd starter next to the best food in the world.

I don't think anyone noticed starter on that pic