Injection nozzle retaining nut socket

[Larry]

Anyone out there have a Cat part number for the internal splined socket that is used to remove the nut that holds the injection nozzle in the pre-cup on a D315 engine from a 955 Traxcavator, s/n 12A4296 motor? The splined nut is about 1" in Diameter. I don't have any info on this unit. Most of the other retaining nuts are hex shaped. This must have been a year all it's own. Thanks in advance, Larry.
PS. Have a bad injector nozzle, that's why a socket is needed.

[edb]

Hi Larry,
the splined wrench/socket is P/No 2H7479.
Scaned below is a pic of the tooling for the Glow Plug precombustion chamber Direct Electric Start engines.
Hope this helps.
Cheers,
Eddie B.

[Old Magnet]

Also goes by the earlier number 8S2243

[Larry]

Many thanks edb and Old Magnet. Have one ordered. Larry.