site.dat , comparing 2 site.dats ?

[dunken]

Did find a older backup , is there any util that can compe 2 site.dat and take all new sites and adding to a new site.dat ?

Or its manual work that is needed for this odd job ?

[MxxCon]

there is no until to automate this, but it's not completly manual work.
if you didn't use encryption(or can temporary remove encryption), sites.dat are text files so you can do diff on them.