Flew ML 737s at least once xSIN-xKUL and/or v-v when I was a kid and the 737s were brand spankin' new. ML had 5 such copies (transferred to SQ of which I have never flown any of its narrowbodies other than lots on its 707s - never on its 727s or 757s) but also looks like ML had 2 -200s (only 1 apparently made it so SQ) so it'd seem I would have a ~72% chance.

Also flew on a LH 737 xMUC-LHR once in the very early '70s. Not as confident it was a -100 however.