Both. Original 8N AMMETER, 30/30, the 'loop' style induction gauge, were steel bodied, brass bezel, painted. Oil gauge, 0-50 PSI, made by The Stewart-Warner Corp. were all steel bodied. Both had bezels painted Ford Semi-Gloss Black Enamel black. FWIW: The early 9N used a 20/20 terminal amp gauge on the first 4000 units, then switched to the LOOP style. Early 9N gauges had chrome plated bezels. Oil Gauge has the STEWART-WARNER script logo on back. I have a bunch of correct, working, original gauges if interested...email me if so.
EARLY 9N ORIGINAL DASH GAUGES:
8N FORD TRACTOR ORIGINAL DASH GAUGES: