I believe you purchased a 1919 NRA. The M 19 was a later speed lock target style rifle in 22 RF and 22 Hornet. (M19 22rf med hvy bbl, M19M 22 rf bull bbl and M19 H Hornet).
As for the 1919s there were at least three variations. Pictures would help a lot.
Some were marked 1919 NRA some were not. In the first model, some were even made in 22 rf short.
If the gun is minty, with a perfect bore, the original magazine (easily lost) and no extra holes you did fine on price. There are quite a few 70% rifles out there but few in top condition.
Catalog reprints are available on Ebay.
This is a third model 1919 NRA with an incorrect front sight.
http://www.auctionflex.com/showlot.ap?co=23431&weiid=5771077&lang=En
