I dunno what I keep pressing!

Anyway - the names (and the pitch) are totally irrelevant - the strings are tuned a perfect fifth apart if you use "the new Italian tuning", or sometimes an equal tempered fifth if you use a crap tuner. Otherwise the standard is fifth - fourth - fifth, for example G,D,G,D (called A,E,A,E, but that's not really kind to the fiddle).
The most important thing is that all instruments are set to the same pitch - so much as it may grieve you, you tune to the melodeon, because it can't conveniently be tuned . If there's two of them god help you!