there are indeed down tube cable stops, which will make it easy to put an old pair of barcons* on there. It may have been converted, but there's also a braze-on "lump" below the dt shifter clamp, as if it were made for either option. It appears they made the same frame for a variety of model fit-outs, and the downtube shifters were the base option - the stem shifters actually came with a higher spec but still entry level Gran Sport De Luxe.



*Assuming my memory of my 8-10 year old parts bin is accurate.