Tim H, Yes, Texarkana Tim is probably near you (ground shipping should be cheap) and he stocks a dizzying amount of Schaeffer's oil. I just switched my Honda 18hp twin cylinder, liquid cooled tractor over to Schaeffer Supreme 7000 synthetic blend with moly in 15W40.
I think 15W40 is one of the best weights for power equipment that has a few years of use under its belt and called for 5W30 or 10W30 when new ... as long as you aren't running it in sub-freezing weather.
Tim should have Schaeffer straight weights still available, though.
You are right, the straight weights are getting harder to find at the mass-marketers ... but I just picked up a quart of Pennzoil straight 40 at a local Walmart. It CAN happen. You might have to check numerous stores, however.
Oh, and AutoZone carried Chevron Delo 400 in straight 30 last time I looked (1 gallon containers). This was a while ago, though. For straight-weight oils, you're usually better off going to smaller auto jobbers that carry more than the typical weights and brands. Look for a jobber that sells Amalie, for example.
--- Bror Jace