The shape of the dropouts look revcore to me, just the bend of the legs near the fork crown look different.
Also double thick dropouts, suggests maybe slightly later than 88.
There does seem to be plenty of differences in revcore components through the years.
I was looking through the thread about the frame you just bought and it has the machined bottom bracket and a flat brake bridge, as far as i can tell. My pro frame has tubular brake bridge and a plain (non-waisted) bottom bracket. There are also subtle differences in frame dropouts, some look very CW in style, whereas others are more of a Free Agent shape.