A possible Celtic reflection of OL Germanic Lyda, Finda and Frya survives in Celtic Áine. This finding requires knowing that Aino, of the male-female Sampo and Aino, or Frei and Freia, pair exists. This realisation became possible only after 1984, when the Aino name for that character was first time recorded down into archives.
Áine = Frya, or Freia-Aino aka Freyja
Aillen = Lyda (letter L features in both)
Fennen = Finda.
Áine's father figure, the all-father Ollathair Dagda associates with all-father Alfǫðr Odin. His female companion Morrigan with Odin's crow and valkyrias. In Finland-Swedish Bock saga the figure corresponding to Wralda (veraldar goð Freyr) would be Frei of Odenmaa land, or even theologically Oden the sun in sky (as Frei and Freia are first humans and their birth is one odenting). Old Norse language reflection of this is the Fennoscandian holy land of Ódáinsakr. As Swedish and Finland-Swedish spelling Oden (warlord god, sun) is the same name as western European Odin (warlord god), this shows us how the Celtic replacement of original Freyr figure by an Odinic figure could have come about.
This seems to suggest both the Bock saga (Freia-Aino) and Oera Linda book (Lyda, Finda, Frya) are genuine old European beliefs as to this element. Thanks go to a Telegram writer, who pointed out the existence of goddess Áine to us.
Edit: a possible source for this Celtic usage of Finnish language is the depiction of Kelta studying under the Finnish leadership (who would have claimed origins from Sampo/Sampsa Pellervoinen and Aino, or Frei and Freia). That OL Kelta segment survived into Celtic lore as the "Tuatha De Danand". Dagda and Áine are of this very same Tuatha De Danand stock.