If there isn't a match it's not a repunched mint mark? And at best if it is I have a 5 or 6 dollar coin
There are a number of unlisted/attributed RPMs. Some dates/mms are more likely to be unlisted. But those tend to be extremely minor and not of significant value. Most RPMs are not very valuable, even in a high grade. But we variety hunters collect what we want...high value or not. Unless your coin is MS65 or better, the value is pretty low. Brian's Variety Coins sells MS specimens for various dates/mms and you might get a sense at what he is getting for coins like you find. Otherwise, eBay Coins has sale prices that could apply. It's always up to the buyer as to what they will pay. But it is somewhat a niche market save a few of the more popular items listed in the Red Book.