Newbie question, year model Options

[ventilator01]

I just bought a porsche 914 2.0, lost title and I have a bill of sale. I bought it as a 1974 but wanted to make sure thats what I have. This numbers is along the windsheild on the drivers side 4742905917 There is a plate under the hood on the passenger side headlight case the only number on it that i can make out is 474. Another tag in drivers side door jam is 4239550. I bought this car as is, and it needs a head ($1500.00 is what I paid for car), was thinking it was just gonna need a head gasket.... but it needs the head and the jug under head. I know I prob got screwed, but really wanted the car. This is my first porshe, will post some pics after I get the head and get it home. Thanks for any info offered. I live in Georgia about 70 miles south of Atlanta
Thx
Steve