Barry,
Is your unit a true 470? I see no part number B1030 in the manual parts list. There is a part number A1030 (more about this at the end of this message) that is readily available from Amazon and others. That is unless they went through a design change and there are multiple manual revisions reflecting other parts that were used. You aren¡¯t talking about the plastic cap at the end of the filter tube nearest the tip end, are you? Hakko only listed that part as coming with the filter pipe kit (part number B1017 describes as ¡°filter pipe w/front holder and filters) which is pure unobtanium. Otherwise it looks like the spring filter (part number A 1030) provides holding force between the front cap and the small filters.
Greg
