You are correct in your assertion that the section from the 1894 act refers to Parish Property, so if you have gifted the property to a third party, regardless of who that third party may be, it would no longer be Parish Property. At the time of transfer, there should have been a legal document defining the terms of the transfer and that document should have included future financial and maintenance responsibilities. A custodian trustee holds no responsibility for the management or maintenance, so you are under no obligation to provide an endowment when transferring the deeds.
Before making any commitment, I suggest that you take a serious look at the condition of the building and assess its social value to your community. Sometimes closure is the right approach, however unpalatable that may seem. I suggest you contact your local ACRE branch (check www.acre.org.uk if you don't know your local branch) as they are the experts in community building management.