The peculiar part is that the serial number is on the bottom bracket instead of the head tube. Most modern 'sonics had the numbers on the bottom of the head tube with the exception of some of the high end Team Europe, Team America etc. models when they had Columbus tubing. Now I *think* the PICS frames had the numbers on the head tubes and often had Tange Prestige tubing.
Is there evidence of an old riveted style head tube badge on your bike? If so, I'm wondering if perhaps it is more likely a '78 model than an '88 model.
Here is a 1979 track bike for reference.
Post some pics when you're able and that may help shed further light on the true identity.