Hi Bob,
I also had a March 1967 250SE high grill coupe in Papyrus White with chrome side trim, so I know these cars well.
14 x 6.5 Bundt (Mexican hat) rims will fit your 250SE without major issues if you choose the right offset and tire size.
Rims:
Original Bundt wheels for W108/W111 had ET30 offset. This keeps the wheels centered in the fenders.
Tires:
195/70 R14 for closest to original diameter
205/70 R14 for a slightly wider fit that still clears the fenders
Avoid ET25 or lower, as the wheels may rub the front fenders when turning.