about the 1000.00 grand watermelon note?

<<<thought i read somewhere that banks only used the note for bank money transfers and wasn't for public use.

Although there has been some currency issued that was only for bank money transfers, the "grand watermelon" Notes were not. There was, however, a restriction. The Notes that could be used only for the purchase of silver, but they could be redeemed in coin – gold coin.

<<<If a family was well to do back then could they have gotten one ?>>>

Yes, as long as they had enough silver to sell to the government.

The Grand Watermelon notes now are incredibly rare because they only circulated in a very limited way. Silver from mines was exchanged to the govt for the grand watermelons. The notes were then almost immediately exchanged back for gold. There just weren't really situations in which someone would get the $1000 note and then exchange it to someone else. For perspective, a car in the 1890's cost about $200 so a $1000 note would buy 5 cars. People don't (and didn't) keep cash like that around the house.

I think that trying to get this note into your story for some reason will just make your story seem contrived.

zman is right in this limited way that a family could have one as long as they had enough silver to exchange to the govt. This isn't silver coins or silver tea sets. This would be silver bullion at about $1/oz. That pretty much means the family would need to be extracting silver from mines or engaged in the business of buying the silver extracted from the mines.