You are right about the wattage. These bulbs are only 25w each, and one of them is used mainly for warming up after I have opened it. It is on maybe for five or more minutes, then off for a minute depending on room temperature. The temp fluctuation is set to 1°C.
The vent holes are there - right under the egg tray in the rear and in front there is a little opening between the incubator and its door - that part below that is not covered with white rubber strip. The third hole is on the top, but it was originally made for a big, tall mercury thermometer - thermostat which I don't use anymore.
I bought this incubator some 20 years ago from someone who made them for sale. I have had at least 20 successful hatches there and none failed. These babies hatched there a week ago: