I'm afraid the set of strings I received were not adequate at all. The core wire of the low A was so that brittle snapped before it was tuned and I returned the set immediately in the hope of a refund. The set seemed to have been made up of suitably gauged multi purpose loop-ended metal strings and unwound and knotted nylon strings. There are two ways of tuning the Guitarron with the high A ascending in pitch or re-entrant (an octave lower). There was no provision or indication of how the set was selected, which was puzzling as the re-entrant tuning is generally preferred and this set did not favour that configuration. They also appeared to be slightly oxidised straight out of the packet, they did not feel nice under the fingers.
I suspect the metal strings were intended for a piano as the did not like going over the nut or around the machine heads. I didn't bother to try stringing up the nylon strings, I was not confident with the knots.
Unfortunately I could only find one other source for Guitarron strings in europe and these too, were disappointing. It looks like I'll have to order from Mexico in future, and hope that Thomann have a word with the supplier and see fit to refund my money.