Yeah. Just not very bright.There appear to be loads of items for sale online that fit the description of your requirements.
Have I missed something?
Thanks dude!!The front indicators are a T15, like you say same wedge size as a 501 but bigger bulb.
I just bought these for the front indicators as i've converted to clear lenses, plenty bright enough at 21W.
2 x Amber 921A Car Signal Indicator Light Lamp Bulb 12v 21w T15 Wedge Capless | eBay
Ah, you know what they say, like bulb ........Yeah. Just not very bright.