When I learned this simple polka I was aware that it could be played in several keys.
(For fellow beginners check out the Session for names, comments, and settings of the new tunes you learn-there is a wealth of information to be had for free.)
Its a fun tune and I played it in G, but the other day for some reason I ‘heard’ the beginning note in the key of D and just started from there.
It came pretty easily just by remembering the intervals.
I know this is a very minor trick to the experienced player but it was a great joy to me!
Progress!!!
Try the same thing by playing tunes in D on an A whistle. Very useful for those tunes that have the odd low note that you can’t get on your D.
I love this polka. Play it in A. Have it in a set I’ve been playing in sessions lately. Polkas are a great way to bring up the energy without playing something too technically difficult. 
While were talking about the Britches I have always loved the Martin Hayes, four part version he got from Joe Bane, on his first recording. I always thought it was Bane,s unique take on the tune ( well it still is really). Then I was listening to JJ Sheridan,s piano cd of music from the Petrie Collection and there was Joe bane,s version though only three parts I think called the Irish Lad’s a Jolly Boy.
Anyway I’d assume that this tune from the Petrie collection has been watered down a bit to the polka we know today (2part).
Enough rambling but if you don’t know hayes’ version it might give some lift to a a bit hackneyed tune.
I like Sheridans piano stuff as well. Would like to sit and play some tunes with him.