Hi Paul,
I have a ticket open with support and here are the criteria they said it needed for it to be uploaded. However mine that fit the qualifications are not there for my Charity store but are with my other stores. I also thought they only needed 3 days remaining so I was glad to get the info. Hope this helps and I will post if they get it resolved where mine are viewable in Google Shopping.
Needed criteria ---
Auction with at least 7 days remaining & BuyNow available
OR Auction with On First Bid & BuyNow available
OR Fixed Price with at least 7 days remaining
OR Fixed Price with Run Until Sold