Jim, I'm not sure I can see what's sub-par about the crema in Bob's shots. For simple ratio, it seems impressive. The color may not be to your taste, but that seems to me mostly a matter of roast. I don't think it's possible to get superior crema from a silvia-class pump machine, or at least not in my experience. Don't mean to be defending Bob; I am curious.
As to pulling a ristretto with a lever machine, in my month with my europiccola I've had no success, for exactly the reason you say. I can overpack my basket, use a longer pre-infuse, and end up with a very difficult pull that produces a very low volume of espresso. It's thick, but lacks decent crema and tastes overextracted. Should say, I'm not a ristretto drinker really in any event, so it hasn't been much of a focus for me. Most often it's happened when I've messed up rather than when I was aiming for a ristretto.
One side note: my europiccola uses far more coffee to produce its ounce or so of espresso than any of the pump machines I've used. It's a different thing, as you know; shorter extraction time, less espresso, more coffee. 2.5 oz in 25 seconds isn't possible, but while the volume is more like ristretto the faster extraction makes it something different. I'm not sure how well pump ratios and lever ratios are going to add up.
Man you ought to hear her with the siren on . . .