Interestingly, here is a comparison of spec sheets of electrically interchangeable Iwasaki lamps compared to the base mercury vapor lamps:
400W mercury vapor:
https://www.iwasaki.co.jp/data/discon/HF400X/10/0001890.pdf
360W high pressure sodium retrofit with thermal starter:
https://www.iwasaki.co.jp/data/discon/NH360L/10/LN410351B.pdf
360W deluxe high pressure sodium retrofit with thermal starter:
https://www.iwasaki.co.jp/data/discon/NH360DL/10/LN410393B.pdf
360W high pressure sodium retrofit with FEC ignitor:
https://www.iwasaki.co.jp/data/NH360LS/10/0000884-2.pdf
400W quartz metal halide retrofit with glowbottle starter:
https://www.iwasaki.co.jp/data/discon/M400LE_BUP/10/L430003A.pdf
400W quartz metal halide retrofit with FEC ignitor:
https://www.iwasaki.co.jp/data/M400LSH_U/10/0000816.pdf
400W high CRI daylight quartz metal halide retrofit with glowbottle starter:
https://www.iwasaki.co.jp/data/M400DL_BUDP/10/L430075.pdf
360W ceramic metal halide retrofit with FEC ignitor:
https://www.iwasaki.co.jp/data/M360CELSP-W_BUD/10/GL09P10-2.pdf
https://www.iwasaki.co.jp/data/discon/M360CELS-W_BUD/10/0001669-2.pdf
https://www.iwasaki.co.jp/data/discon/M360CELSH-W_BUD/10/KLS410030-1.pdf