M_Boats: M15 Ports

I am in the process of having new Ports being cut to shape out of acrylic. I will have to drill mounting holes in the Ports is there any thing special I should be thinking about. I have been told to use a very dull drill and slow speeds. In addition when I removed the old Ports I found that there was what appeared to be felt gaskets between the Port and the cabin hull with very little if any sealing material around the edges. The gaskets seem to be good condition. Should I just remount the new Ports using the existing gaskets? George M15 #602 NoNameYet