Whahoo success!
Finally got to my goal, the damn thermostat bypass hose. After removing the radiator, condenser, water hoses, heater hoses, air hoses, air box canister, fan and alternator, three bolts hold on a separate alternator bracket that sits above the A/C bracket. The bolts evidently go into the block since coolant dribbles out. Also, be aware of the spacers found on each bolt holding the separate alternator bracket to the engine.
Evidently, unlike what I would guess most 280SL models have for an A/C-alternator bracket, the 230SL, or at least mine, has a separate alternator bracket which allows access to the thermostat bypass hose.
Two questions:
Does it sound reasonable to leave the A/C bracket in place and simply remove the compressor, idler pulley and A/C belt?
Does anyone have any experience good or bad with a "GRAF" water pump?
TIA