Well...there's several variations of T-Walsh out there, solving different kinds of problems, some of them creating other problems of their own. In some 1♣-1♦-1♥ shows "any" 11-13/14 and 1NT (17)18-19, in other the 1♥ rebid show exactly 3c♥. In my version the 1♥ rebid shows ANY hand with 3, 13-14 with 4 and most 18-19 balanced with 4.... As to the problem, with my new regular partner (I've got two regulars now) with whom I play Walsh, not T-Walsh, I'd rebid 1NT, since 1♠ promises an unbalanced hand. With most non-regular partners in my area I'd rebid 1♠ either playing up-the-line bidding or Walsh.