I was lucky to find a early HW80 cylinder with just a two hole arrestor block,needed to find everything else for it,the stock is a fine example of a mk2 ,having no serial numbers to go by so unable to say if it was .22 or as it is now in .177 with a brand new screwcut barrel fitted ,asked for a valuation at my local RFD £325+ was the reply.I let my granddaaughter use it as she is careful with it so I would say, let the lad use it supervised by yourself its value can only improve ,mine is a keeper all day long