If it really is a "90SL" then that would be real rare! A 900cc convertible. I suspect that it really is a 190SL that someone has tried prising the badge from and broken off the "1" (or possibly a typo SPOCK?).

190SLs whilst not common, aren't real rare here yet either, at least not among club members. In Oz they currently range from around $30k AUD for roughies needing restoration to around $75k AUD for the best (or the dreamers). My father-in-law wants to sell his 1960 190SL which has no soft top due to his insistance that the chassis number implies it was built as a coupe (removable hard top). He is fussy about originality and it is a concours award winning car. He is asking $55k AUD and you can see a pic over on the Cars for sale forum.

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107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.