Oh I feel so bad for you! I had/have a similar problem.
When preparing for our marriage we had to tell the priest where we both were baptized. Luckily, it was the same parish and thank goodness they actually had the baptism records.
But our first communions, his confirmation- no record at all.
Maybe in some parts of the country First Communions aren’t recorded but this was a huge problem for the parish that wanted to marry us. The funny thing that parish was the one I went through First Communion with! I told the lady at the church and she’s like “Oh I’m sure Father remembers.” I’m thinking “Yeah right, he’s retired and this was almost 20 years ago!” What do you know…he didn’t remember.
I wasn’t too upset until they started choosing their words very carefully about my husband’s confirmation records. It became very clear to me very fast they thought he was lying about it.
I finally lost it with them and informed them we had no reason to lie as they couldn’t refuse to marry us since we were both baptized and the priest has signed off on our completing pre-cana and furthermore it was obvious keeping records was not at the skill-set of these parishes.
I had to go through RCIA anyways because I was never confirmed- so why would we lie about my husband?
Anyways, they married us without another complaint- then sent us back to our home parish. They were probably as happy to get rid of me as I was to get rid of them.
So to make a long story short- if my experience is any indication you’ll probably have to go through RCIA, just think of it as bible study.