i've heard many wa speakers use մուկեր, ձուկեր, etc... i don't know what's the "proper" usage in wa, but in modern ea, the formal usage is մկներ, ձկներ, մատներ, դռներ, գառներ, etc... i believe this is left over from grapar, where these words were originally մուկն, ձուկն, դուռն, գառն, մատն, etc and received the regular եր by default... this is more abvious if you look at other words such as դռնապան or գառնարած... you can clearly see the ն... it's not դռապան or գառարած...