In the O/E History-Header View make sure you are showing the Order Key field (which is the Doc # prefixed with an I, O or C).

In the O/E History-Detail also show the Order Key field and then link the Views on the Order Key field not the Doc #

If the Link from your Customer File to your O/E History-Header is on Cust # then this sould be very quick and only display History-Headers for that customer.