The Structure of PAN and TAN has been designed scientifically. Like 5the alpha in case of Individuals, is the first letter of Surname. In case of non-individuals, it is the first letter of name. So is the 4th alpha of TAN. There are many other codes also .. like for individuals, fourth alpha is "P", Firms-F, Companies-C, AOP-A, HUF-H, etc etc. There are many more codings in alpha and nos which is not a point to discuss for your qn. In case of proprietory business, it is the proprietor who is issued PAN, not the business/trade name.
Because of these codings, logically, PANs oand TANs of one may not be transferable to other through correction.
Moreover, since the firm is no more in existance, i think, all its PAN or TAN should be surrendered and only if the proprietor is not already having his personal PAN & TAN, he should apply afresh.