Again, they are both double filament. I have a package of each bulb right here. Sorry, but they do interchange. The wattage difference is in the milliwatts. It won’t cause any melting. The wattage of the bright filaments is the same. The only physical difference is slightly different resistance readings of the parking light filament. There is no brass colored area. These are wedge plastic base bulbs. These are not the old round twist in type bulbs. See link below for a picture.
http://automotive.hardwarestore.com/87-541-automotive-bulbs/auto-bulb-replacement-112194.aspx