Rich,
Most toggle switches are designed for 3/8" or less panels - is a physics
things for the toggle arm. To make a barrel longer would require a dbl
pivot - and I have never seen one of those.
In addition to the ideas of a cover plates mentioned, a common way is to
drill or route out a relief from the backside that the body of the switch
can be placed into - a 'switch well' if you will... Thereby leaving a
thinner thickness for the barrel.
Another idea? You can get rocker switches that have a paddle on them -
those mount from the front, but might also would have some troubles with a
3/4" thickness. But it would 'simulate' a toggle switch in some way.
Perhaps this is one reason why the old Corse Healy pull-push switches were
used so much back with wood boats..
Best of luck, sorry there does not seem to be a simple solution for you....
-al-
Viking Star
45' Monk Sr. / McQueen
mvVikingStar.blogspot.com