A couple of other things come to mind...

Some sellers don't describe exactly what model they have (Mk2, Mk2a, Rio Car, etc.). That seems to be a question that pops up a lot...

How about including an overall description of the condition, maybe from a list of standardized or pre-defined phrases like "Mint - Never installed" all the way down...

I definitely like the 3 day shipping rule as one of my Empegs took over a month to hit my door after PayPal payment was made (bought from the For Sale board last summer)...

Thanks, Randy