I have the book, they definitely aim at caighdeánized spelling (including writing Gaeilge, dearthair, an-mhaith instead of ana-mhaith etc.). But afaik the grammatical forms, idioms, and most definitely the pronunciation taught, are Munster (but it’s not conservative Cork Munster like in Peadar Ua Laoghaire’s books, or in the TYI 1961 – I think it might try to teach more modern contemporary Munster Irish spoken in Dingle? But I am guessing here).
Anyway, I have made a pdf with all the reading texts from the book and vocabulary (the vocab translated to English), and posted it to the Facebook Irish learning group Foireann Gaeilge.
I might upload it somewhere else, or share it otherwise, but I don’t know how ok that’d be copyright-wise. I myself wouldn’t mind sharing it, though, as the book is out of print for many years anyway, and afaik never been available outside Poland.
I've also started making a Memrise course based on the exercises from the book, but have stopped for the time being. I hope I’ll get back to it, though.