Welcome Dee!
It's most likely a National made machine. They bought out Eldredge and contracted with Montgomery Wards to produce their machines. Brunswick was an old MW brand.
The needles are 20x1. They come in Rotary or Long Bobbin (VS) styles. I don't know the difference though. They're usually available on Ebay.
This seller is also a member here. I hope I'm not in trouble for posting this. The rules about selling here are strict.
http://www.ebay.com/itm/National-Eld...item33a55bb6b1
His name is Jon though his username escapes me at the moment.
He can tell you the difference between the needles.
Rodney