With respect to all lands bid off for taxes in the name of the county at the tax sale of September, 1940, or prior years, and now held by said county, the owners, holder of record title, his or her heirs, executors, administrators, assigns or mortgagees may, at any time before September 1, 1941, redeem said land by paying all of the delinquent taxes thereon without the payment of any penalties, costs, expenses or interest which are hereby remitted. In case redemption as provided herein is made by a mortgage holder, the mortgagor or his or her assigns may redeem from such mortgage holder or his or her assigns, upon payment of the amount of the taxes paid by such mortgage holder with interest at the rate of six percent per annum from the date of redemption by such mortgage holder.