is it Irish traditional you want to play on the melodica? I find the Clavietta less suitable for trad, unless its a slow air, or song. It’s easier to get a ‘bounce’ for reels and jigs with the other melodicas (Hammond, Suzuki, Yamaha etc) which have reed plates similar to mouth organs, rather than the separate reeds of the Clavietta.
Would be interested to see what you think of the Clavietta. They don’t all need work by the way, sometimes they’re in tune and completely airtight. Luck of the draw!