I don't know about the 123 chassis, but the removal of the wood center consol is pictured in the stereo removal article under the DIY tab at the top of the page. You might look at that and see if they are similiar. My 124 fekt "stuck" as well, until I discovered that several switches are clipped onto the wood, and plug into the chassis beneath, and that this was the resistance I was encontering (there is also a screw under the carpet at the back on 124s). Like I say, your 123 may be different, but it is worth a look, maybe.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
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