60's Oldies are NOT totally dead.
But, one needs to be careful how you play them.
Same for the early years music, too. You see, the point of such a format is that, at least some of that music transcends the test of time. Could you be a radio station playing music "from the start of rock and roll, to the start of M-TV" and not, at least occasionally, hear "Jailhouse Rock" or "The Great Pretender"?
The fact is, you can play them and get an audience. But you have to be careful how you schedule them, so your demos don't get top heavy with aged demos, or play next to the wrong songs that makes them all sound like train wrecks.
The trick is: find the early years songs that are, truly timeless. Play them, and leave the others to specialty or syndicated shows. For the 60's, drop all the novelty crap and find the songs that are becoming timeless and play them. Play them all...sparingly. They're a "feature" and the "spice" of the format that gives a station credibility with listeners in the upper demos, and with those who are there to live the history of rock and roll. Researching your music will show you the way on this.
But, there's no doubt the "meat" of the oldies format now is the 70's and 80's and must be so. (And sorry...the 80's happened some 30 plus years ago...those songs are now "oldies". Get over it.)
80's music has gone two different and easily definable directions for mainstream audiences. It's not difficult to figure out some of the obvious oldies-centric titles.
Like the old saying goes: you can't play everything. But, you can play a sample of it and still hit the demos. If you schedule and image it all correctly.