I do not believe that the following class of words (if it even is a class) has yet been described: verbs, the simple past tense of which is also homonymous with, or at least homophonous, with, the simple present tense of a different verb.
Galef, Daniel W.
"I Wroted Up This Ditty, And Sanged It Nice An' Pretty,"
Word Ways: Vol. 46
, Article 14.
Available at: http://digitalcommons.butler.edu/wordways/vol46/iss3/14