After lots of research, reviewing shop manuals, etc, talking with two vintage Mercedes specialists (one who is ridiculously qualified and we'll known), and adjusting and driving three 230SLs it is clear to me that strobosonically setting with a timing gun a 051 distributor at 38 degrees BTDC at 3000rpm on a 230sl will turn the vehicle's motor into a grenade if the motor is driven hard to redline as it was designed. Works great until about 4000rpm or so then pings to the point that motor is going to blow holes in the pistons. This is on all three 230sl's tested.
In California, where we have 91 octane (which is about 3 below what Mercedes specified based on their 98 European octane rating), we must set timing to 28 (twenty eight) degrees BTDC MAXIMUM. All three vehicles were used to experiment. At 91 octane.....28deg BTDC is it....38 would result in fireworks. There may be a misunderstanding between the various distributors which is is resulting in confusion.