Here's the detail dimension drawing for the Rohn 25G section:
http://www.radiancorp.com/ROHNNET/rohnnet2004/html2004/index.htmlIf your tower dimensions are the same or very close to that, then the standard Rohn P/N A25G rotator plate should work for you. It's strong, it's prepunched and predrilled for all popular amateur rotators, it's very well galvanized, and they last about 50 years. It's not expensive.
WB2WIK/6