I hadn't compared the two - the G/S style and the regular airhead style - but think they're way different and not interchangeable. Usually I notice things like that.
It is possible to mount the regular airhead gauges on the G/S (seen it done) so know it can work - and it looked pretty good. Don't know how they'll survive on a G/S though. But you mentioned wanting to keep the bike stock, so that option is out.
Wanted: Dead, smashed, crashed or trashed gauges
BMW GAUGE REPAIRS - TACH*SPEEDO*CLOCK*VOLT METER *PODs & LIGHT BOARD*