Typically you'd use the cp_merge tool to do this, but cp_merge does not appear to be supported in R80 from my experience. Just bringing in the objects/policies during an upgrade is sometimes desirable after many many past upgrades on the same SMS, especially when you'd like to retain the default global settings for the target version and avoid bringing any possible old cruft forward.
I'd guess you could do a migrate export on your current SMS using the R80 migration tools, import the config into an intermediate Virtual Machine running R80, extract just the objects/policies from the R80 VM's mgmt_cli in command/text format, then import those commands into the target SMS's config via the mgmt_cli. I don't think there is any kind of existing tool to do this, but something like this sure would be handy...
My book "Max Power: Check Point Firewall Performance Optimization"
now available via http://maxpowerfirewalls.com.
New 2-day Live "Max Power" Series Course Now Available:
"Gateway Performance Optimization R81.20" at maxpowerfirewalls.com