See here: http://www.escholarship.org/editions/view?docId=ft1×0nb0dk&doc.view=content&chunk.id=d0e26300&toc.depth=1&anchor.id=0&brand=eschol

Obviously this inscription doesn’t involve the Technitai of the Isthmos and Nemea, and if Kallet-Marx’s spacing is correct, Poplios Kornelios is a few letters too long.

I’ve got Le Guen on my list of books/articles to look at, for which there is a BMCR review here: http://ccat.sas.upenn.edu/bmcr/2002/2002-07-16.html I won’t have access to it for a couple weeks, so it will have to wait until then.

As for how it made its way to Korinth, I don’t know. Gebhard and Dickie (Corinth XX 261-78, which I haven’t seen yet either = SEG 51.339) have examined the activity at Korinth and the Isthmian sanctuary of Poseidon between 146 and 44 BC, and they included Fragment A in their discussion (which apparently means they also dated it later than Kent did). I’m hoping they can shed some light on your question. The only thing I can say at the moment is that neither the Isthmus nor Sikyon are that far from Korinth, so it could have been transported from either site at some point, possibly when the responsibility for organizing the Isthmian games was transferred back to Korinth.

I should also mention here that I’ve just run across another extremely interesting inscription that will have a bearing on the discussion: IG VII 2414 / IG VII 2413 (I believe the two have been associated). This inscription is interesting because it was found at Thebes, which apparently was the base of operations for the Athenian Technitai, and of course it appears that it comes from a Roman consul (στρατηγὸς ὕπατος Ῥωμαί[ων]). Obviously I’m going to have to do some digging on this and see what others have said, but Sisenna was never a consul, and Lentulus was consul in 130. I think this inscription may be Lentulus’ ruling. If so, then it appears he made a ruling on the Technitai of Thebes while consul in 130, not praetor in 128, and if our inscription from Korinth relates to this affair, then we may want to restore [στρατηγὸν ὕπατο]ν Ῥωμαίων at the end of line 2 and beginning of line 3 and date it to 130 along with Syll. (3) 704B). As it just so happens, I was thinking that it should be dated to 130 anyway, because line 21 of FD III,2 70 talks of the first meeting to discuss the issue as being ἐπὶ Ποπ[λίου Κορν]ηλίο[υ], which when I first read I thought must refer to his consulship. In fact when I first wrote up the post I wrote 130 BC?, chose [ὕπατο]ν as my first restoration, but then I read Pickard-Cambridge (who follows Daux), and they placed it in his praetorship, so I thought it safer for the moment to follow Daux/Pickard-Cambridge.

Do you have any idea how this inscription made its way to Corinth, if it refers to the dispute of 134-112 BC ?

The figure LXII which is also in the Lex Coloniae Genetivae Ursonensis (in a different context, it seems) shows the limited value of parallels for such a fragmentary inscription.
Having said that, it remains a fascinating document. Thank you Paul for allowing us to comment on it.

καὶ αἱ δεδομέναι̣ [τιμαὶ τῶι τε δήμωι αὐτῶν καὶ τοῖς δικασ]-
ταῖς καὶ γραμματε̣[ῖ ἐπιφανέστεραι πᾶσιν ὦσιν, καὶ ἐν ἀ]-
ναγραφῆι…

The other possibility is that this really isn’t of foreign origin and the Korinthians were honoring foreign judges. Unfortunately the decrees of Korinth are so few, that it’s difficult to know whether the koine absolutely means foreign engraving.