Purchase of unregistered partnership firm by an individual

Dear Members,

I need some clarifications w r t following:

1. what are the formalities of purchasing a unregistered Partnership company(roto gravure printing)  which was started operation from 17th June 2011?
2. which was purchased from a Proprietor who had surrendered VAT, Service tax , ESI and PF registration due to business loss continuously since 2005 and hence closure in May 2011?
3. New partners changed the name of the firm, obtained afesh VAT registration, afresh Rental agreemnt with land lord  and  new Bank account and operating since 17th June 2011
4. Now they are unable to run the firm and wish to sell-off machinery and other associated assests

under such circumstances what are the legal precautions to be taken while purchasing such assests by limiting liabilities if any which are not known as we wish to continue the " Name, VAT registration and Bank accounts?

Rgds

Hemaraju

e-mail: vhemaraju@gmail.com