Peter, the 1/2" variety is available from
http://www.glen-l.com/inboard-hdw/sw-gauges.html
You need part number 90-975. Don't worry about it saying 100-240 degrees, because the Deluxe gauges just leave off the number 60 down at the bottom of the gauge. I didn't know what size hole you had, but I'd rather see you get the correct sender instead of having to use an adapter. Just glad I could help out.
