Originally Posted by JAG
I think the solvent dewaxed heavy paraffinic distillate, which is Group I, is carrier oil from the additive package.
https://www.machinerylubrication.com/Read/472/base-oil-industry
Oils considered to be full synthetic can use Group I for this purpose since it's not considered to be used as a base oil. I do not think Group II is used as additive carrier oil due to lower additive solubility and higher cost, relative to Group I. Using Group II as a base oil in a full synthetic is a big no-no, from a pseudo-legal standpoint.
For the bottom CAS #, from Shell, I find:
Originally Posted by Shell
Shell Process Oils linked to CAS number 64742-65-0:
-HVI 55
-HVI 60
-HVI 65
-HVI 105
-HVI 160
-HVI 170
-Catenex S 532
-Catenex S 541
-Catenex S 925
-Catenex S 932
-Catenex S 946
Which, when researched, yielded:
Originally Posted by Shell
Shell Catenex Oils S are paraffinic process oils manufactured via the solvent extraction process.
They are general purpose process oils used as extender or carrier fluids
So I think you are bang-on the money.
The 2nd from the bottom is as I noted, Group III, which appears to be in very low volume in this product.