Canadian General Electric H125DX42

Here's the lamp I got back in 2009, finally running on the proper ballast six years later!

125W lamps are really not a common thing. To my knowledge they were never listed in US catalogs. They were probably only sold in Canada for a short while before being discontinued. The few ones still operating H42 fixtures have no choice but to order the HF125PD lamp from Iwasaki, which I also have (but it won't stay lit past 35V-ish o.o )