I have tried as well to obtain some specifications about camshafts. The Mercedes Data Book 1969 gives Valve opening and closing angles for several camshafts. The camshafts installed on US version of the 280SL are p/n 180 051 08 35 with a base circle of 34 mm and a lift of 6,5 mm.
The 09 camshaft (used on some Euro models 280SL/8 & 300SEL/8) has a base circle of 32 mm and 7,1 mm lift(actual measurement 7.05) for the exhaust, 7,6 mm (actual 7.55)for the intake. The maximum lift is limited by the bearing diameter of 48 mm. Does anyone have the base circle and lift for the 230SL cam p/n 180 051 84 01? The critical measurement with the head installed is to check the minimum clearance between the intake valve and the piston at 5° after TDC. The exhaust valve is no problem, it has about 12 mm until it touches the block.