For the price of a couple of Big Macs it's got to be worthwhile and it'll still be around after the burgers are gone, but as above be prepared to spend putting things right.
First thing to do is change all the cables, then look at the tyres for any signs of age related cracking. If OE they'll be cheap and not very puncture proof.
Next check all the bearings, BB, hubs and headset. All that assuming you want to keep and use it regularly.
Before all that I should have mentioned check the seat post moves in the frame and not seized. This could scupper all your plans unless the seat is your height.