I don't know about the Tommasini, but the 'hole', in the top/seat tube lug is nothing more than
a 'peephole', on my '86? Montello. (no room to stick anything, let alone one's finger.)
My Ambrosi ('85/'86/'87?) has both the rear brake cable 'buried' (ala Pinarello) as well as the
rear mechanical cable. (chain stay)
In order to fit both cables through their respective tubes, a small 'kink', was put in the wire
about 1 inch from the end, measured for app length, fed through the tube, and slowly rotated.
Top tube, no problem; chainstay, maybe 2 minutes. once finished, the o/s cover is installed.
Regards,
J T