I am looking for somewhere to offer my Marklin train components for sale without breaking the rules or offending the membership. Any referral would be appreciated unless I can list them here.

Normally, people are active in the forum before they offer goods for sale.
Somebody who joins and then the first post is "I want to sell" is looked down on my the administrators due to prior experience.
Perhaps it would help to tell us a little about yourself and how you came across the Maerklin items that you wish to sell.
The forum might also be helpful in identifying some items you might not have model numbers or description for.

Regards

Mike C