Good advice Alan, and thanks to Rick (long time no see!) Rasdan, khalifah muda, Gustav and Moshah for your comments and idear's.
At this time we have been adviced that the gold cross also occur in Sumatra and we have a cross on the underside of a gonjo in a Malay piece posted by Blue Erf.
It has also been established that any of the translations of Tapak Jalak really does not have anything which relate to the cross in translation.
That said, we still do not know just what it is doing on the top of the pesi and what it stand for.
Allow me to restate my questions a little more in detail;
In what time frame did this occur? is it still being done

A little piece of information most of the pieces but not all, I have seen this on were Nom-Noman. Was it also done outside these places and this time period, prior or later?
We have been informed that it occur in Sumatra pieces, are these pieces made in Sumatra or are they imports from Jawa

Do anyone out there have a photo of a Sumatra piece with Tapak Jalak?
Perhaps Blue Erf have recent information on his blade with the cross under the gonjo, which would explain the cross?
If not perhaps some of our friends from Jawa will join in
Thank you!