Help identify DT Swiss wheels

I have 2 pairs of ER 1400 DICUT db21 wheels, which I like very much, but I would prefer to use a cheaper wheelset as a winter training tire. A friend of mine is selling a very similar wheelset for a good price, which he took off a bike he bought 2 years ago. I am thinking of buying them, but I need some help as I cannot find any information about them online.
They are ER 1600 DICUT db21 wheels, which I find rather confusing because I thought that only the 1400 series were DICUT, while the 1600 series were SPLINE.
The only difference I can see between my wheels (ER 1400 DICUT) and these ER 1600 DICUT is that mine have 240 hubs, while the other set has 350 hubs. But are the rims the exact same RR421 (welded, with 20mm internal width and asymmetrical valve holes)?
I know that the more widespread ER 1600 SPLINE db 23 wheels have sleeved rims instead of welded ones (as the ER 1400 DICUT db21), but I’m really confused by the ER 1600 DICUT db 21. Does anyone know these wheels?

Most likely these are an option they only offered to bike manufacturers, not consumers. So you’re unlikely to find info on them online. But it seems like just a unique combo of rim and hub. I think you’ve figured out all there is to know about it.

I believe those are OEM versions of your wheelset, which have the lower end hub.

Yeah, it turns out they are OEM, with the welded RR421 rims used on the (by now previous generation) 1400 series, but with 350 hubs instead of 240. I do wonder about the DICUT version of the 350, as those seem strange. I mean, I’ve seen plenty of 240 DICUT hubs and 350 SPLINE hubs, but no 350 DICUT hubs.