Numbers matching...?

Hey everyone,

After purchasing my first classic MOPAR, '73 Cuda 340. I took it to a local restoration shop to have it looked at after I drove it almost 1300 miles home. The guys at the shop are replacing some gaskets, oil pan, tank, headers and some other minor stuff to keep me on the road. The car is a nice driver quaility and I just need it to be that, a driver. However the restoration shop guys stated that its an all original, numbers matching engine, 4 speed trans, and rear end.

My question is...What does this mean to me?
They said its a perfect canidate for total restoration but what would make it worth that?
Is it worth more money how it is now? Its not the origal color inside or out but is still in nice shape.
Any and all info on the subject would be greatly appreciated!

Thanks
Mike