The Colonial Needle Company has needled that will date from Civil War time. Why don't you contact them and ask how you might geta few to use in your demo.
To my knowledge you can't sharpen needles. However ask the people at colonial if you contact them. Also since it sounds like you are making a utility quilt. I dint believe the quilter at the time would be concerned about the size of the stitches, but do even stitches and larger than normal to get it done and on the bed. You might explain that to those who ask.

I use a #10 between. It works great for me. I'm still working on consistency with my quilting stitches but have tried smaller needles and have trouble threading them since the eyes are smaller.

You don't sharpen embroidery needles. You need to get new ones. I would suggest taking it to the store with you and holding it up to the various needles on the rack and seeing which size it is.

Do NOT use candle wax (unless it is a raw beeswax candle)!! Get Bees wax. You can often find it at JoAnn's or you can contact a local bee keeper. It is sold in a little disc and you run your thread through it.

W&N batting is about as far from authentic as you can get. It is needle punched cotton with a polyester scrim. It is nothing at all like the batting of the 19th century. Unless you buy bale cotton or carded wool and spread it yourself you will have to work with modern products. If you are truly trying to be close to period, use mountain mist blue ribbon cotton or wool batting. I think you will find it much easier to needle and it probably won't dull your needles as quickly.

Just a quick note...

I have tried many different needles, and have found a favorite. My favorite hand quilting needle is "Clover Black Gold", size 10.

Steve

I'm still open to finding the right quilting needle. Where did you find these?

Ok, so I googled Clover Black Gold needles and got a price range from around $3/pkg to $33/pkg. Which one do you like and recommend?