Jolla C2 is actually Reeder S19m Pro S. Its the same device. Difference is only in colour and some markings. So its absolutely ok. Jolla C was Intex Aqua Fish with another LTE Modem Firmware, Jolla Tablet was Aigo X86 with bigger eMMC and better display.
The one and only phone entirely created for Jolla by an OEM was Jolla Phone (Jolla 1) which was never sold as another phone in the Market.
And I just realized this has been changed(?) in 5.0.0.43:
nemo@PGJollaC2:~ $ ssu s
WARNING: ssu.ini does not seem to be writable. Setting
values might not work.
Device registration status: registered
Device model: Jolla C2 (s19mps / c2)
Device UID: xxxxxxxxxxxxxxxxx
Release: 5.0.0.43
Domain: cbeta
Brand: Jolla
nemo@PGJollaC2:~ $
But Bugger! doesn’t pick this up because it reads /etc/hw-release. I look into it.
I’d say that’s factually correct, though perhaps not really relevant. The reason, in my opinion, is that the hardware ID is there to make reports findable. Having some bug reports or answers the refer to the C2 and others to the Reeder S19 only brings drawbacks. Since we normally call it C2 here, we stick to that name.
(Of course, if someone asks “Which device on the market is the C2 actually based on?” then we do need to refer to the Reeder S19.)