You might try contacting Lauerman Audio Imports, the company which imports Rega products into the US. They may be able to provide you with a template that you can use to drill the holes. Here's the contact info:
Lauerman Audio Imports
519 Noelton Drive
Knoxville, TN 37919
Tel: (423) 521-6464. Fax: (423) 521-9494
Lauerman Audio Imports
519 Noelton Drive
Knoxville, TN 37919
Tel: (423) 521-6464. Fax: (423) 521-9494