They all look like Whisplers to me. I will assume you are not located in the USA. Saying what country you found the marbles in is often helpful. Collectors in the USA see marbles in the frame of reference of being found in the USA.
...so the marble is 13/16 in reality and you are positive without a doubt it is older than 2003... and yet you had no clue? I throw my hands up in the air. I don't think it would matter if I showed you 20 exactly like it.
Let me correct myself on the proper spelling “moldy.” Originally called “shield.” I have been calling them Moldies which is correct for plural. Found in same places wisplers are found, but much less common.
Euro Mouldie/Moldie. They are a patch structure marble I have only seen in one size. There is mottling on every single one. I wouldn’t be surprised if we figured out one day that they were made by Irene Manufacturing in England, but maker is unknown at this time and that is a complete guess on my part. One of the Euro types I never see in the USA.