Yup, with the 87 and 88 mix component set, it would have lead me to suppose that the "09" serial number might have been a trailing 89.
BUT, the photos I've seen of late 80's Masi on the web have a big M cast into the BB rather than MASI across the front, and they all have brake cable loops on the top tube instead of the '92 style (like my Tommaso) hidden cable.