Where any registered society is entitled in equity to any hereditaments of copyhold or customary tenure, either absolutely or by way of mortgage or security, the lord of the manor of which the same are held shall from time to time, if the society so require, admit such persons (not to exceed three) as such society appoints to be trustees on its behalf, as tenants in respect of such hereditaments, on payment of the usual fines, fees, and other dues payable on the admission of a single tenant, or may admit the society as tenant in respect of the same on payment of such special fine or compensation, in lieu of fine and fees, as may be agreed upon between such lord and the society.