Maybe you all know about this already but when I have searched on Abebooks or elsewhere for older Irish books (i.e. books printed with any uncial font) I substituted some letters with what appear to be oddly written letters in a "normal" font and have gotten some good results. For example, the uncial "d" and "g" look like "o" and "s" to a bookseller who is not familiar with that font. I found three or four books that way.

Same for dotted letters: Gaeḋilge -> Gaedilge (instead of Gaedhilge)