Everyone, thank you for your replies... this is all so new to me working on A) a diesel and B) a Mercedes. I'm quickly finding that there is a wrong way and a "Mercedes way" in doing repairs.

Peanut butter on the door handles.... that actually makes sense as the bonding resin in that handle is basically a plasticized hydrocarbon, the peanut oil would add back oil that was in the compound that has been lost, giving it that faded/dull look. I've had success using WD-40 to fix solvent damage to polystyrene plastic.

leathermang.. point well taken about suggestions made in replies. Guess I'm a bit paranoid after an experience on another board, we had an individual that maliciously posted plausable sounding advice that led to people ruining what they were asking for help on.

Being a newwbie the wacking the seat frame suggestion to motivate it to move sounded like it would have damaged, if not broken the gear mechanism, so I though it was a real off-the-wall suggestion.

By no means do I want to offend anyone on this forum, especially being a newbie.

Anyway... I've obviously have much to learn with the 126 chassis and 617.95 diesels.