I bought the small basic mold from New England, it is supposed to hold a 2lb cheese. I made a 2-gal batch of farmhouse cheddar and it wouldn't all fit in the mold, I had to use the basket mold that came with the hard cheese kit. I'm not sure but about now I might be able to fit it all in the one mold. Can I do this or should I just leave them as two cheeses?
I would leave it alone. I don't know how much time has pasted but probably enough to chill the curds to much for a proper mesh. When you add curds you can put the folloer on every now and then and give them a good push to get more in there. If you still don't have enough room that means you got a really good yield. That is great.
Lennie, I agree with Deby that too late to join the two (especially as this post is several days after you made the cheese ;)).
It could mean you got a good yield (http://www.cheeseforum.org/Making/Milk%20-%20Yield.htm) or that the curds weren't shrunk/de-wheyed enough before placing in hoop.