I think I got lucky. I was looking for an Xbox below 1.6 to do a RAM upgrade on. I found one with the X3 front switch panel for the same price as any old Xbox without it. Just got it and it turns on. The chip turned out to be the newer CE version. But it's installed with the Xapt3r adapter. In https://command-tab.com/static/x3_ce_v10_v16.pdf there is an image of the standard kit:
The parts that came with this Xbox are 1, 2, 3, 4 and 7. If I want to solder it I will need 9 also. That I can make myself from one of the scrap headers I have. But what is 8 and 10? My guess is that 10 is irrelevant. Is 8 for some drive activity led flashing? Is it available to buy somewhere?