FileMaker doesn't have "cards" so I will substitute "records" where you have put "cards".
Will the same object be evaluated by more than one dealer and you need to list them all?
If so, you need two tables:
Objects::ObjectID = Valuations::ObjectID
You can place a portal to Valuations on your objects layout to enter and list all the valuations for this object.
I'm not sure which valuation total you want here, the insurance value set for each object or some kind of total from the related list of individual valuations.
To compute a total insurance value, you can define a summary field in Objects that totals the insurance value field.
The method I have described works with FileMaker 6 and also with newer versions, though the steps you follow in setting this up will differ slightly due to FileMaker 6 being limited to one file for each table where later version aren't and due to the fact that recent versions have a different method for defining the relationships.