You can learn quite a lot from looking at non-English versions of Wikipedia.
For instance the German Mithras article is quite a bit superior to the English one in several respects, handling the Mithra-Mithras dichotomy well. It lacks the heavy referencing that I added to the English one; but since all that work did not save the article from deliberate poisoning by a troll, it has to be asked whether it was a good idea anyway.
Looking around these articles, I am struck by the number of images of tauroctonies which are language-specific. There were some quite useful images of various sorts.
But quite accidentally, I came across something else. We’re all familiar with “Soli Invicto Mithrae” in inscriptions — “to the unconquered sun Mithras”. But did anyone know that Serapis is also treated as a sun-god? This image says so:
Apparently (for this is Wikipedia, remember — the encyclopedia edited by anybody) this is CIL XIII, 8246. The text is:
CVM SVA CLINE
IN H(onorem) D(omus) D(ivinae)
L(uci) DEXTRINI IUSTI
FILIA AGGRIPP(inensis) D(ono) D(edit)
To Sol Serapis
And his throne
In honour of the imperial house,
Daughter of L. Dextrinus Justus, from Colonia Agrippinensis (Cologne), gives (this) as a gift.
It indicates how “sol” as a descriptive term has very little distinguishing power, between one deity and another.