Hello Ron.
I did not have any clamps available to use on my TT when I drilled. I discovered that the TT stayed rock steady when I was performing the drilling. The secret is to put the TT chassis and cavity on top of a round-bedroom wastebasket and put the rubber underneath the wastebasket to dampen any movement. Make sure the wastebasket is plastic and durable!!!
However, you do bring up a good point which makes a good suggestion - if you have clamps at your disposal which you are confident that it will not leave marks on the TT, especially during the drilling process, see if you can make use of it to keep the TT steady during the drill process.
More to comment later.
Whoever is responisible for making this thread a sticky - thank you! I planned to request this at some point after completing my article.
Anyone who thinks CDs sound better needs to listen to my system. Besides, my cables sound better than yours.
Technics SL1200-MK2 SE-1: MN Bearing + Baseplate + AL/CU Platter, Paul Hynes SR7 Power Supply, Isonoe Feet, SME V, Audio Technica AT33EV, CableMaker 1 Tonearm Cable
Technics SL1200-MK2 SE-2: MN Bearing + Baseplate, Copper Mat, Paul Hynes SR7 Power Supply, Isonoe Feet, SME 309, Audio Technica ATOC9/MLII, CableMaker 1 Tonearm Cable