I don't think you can do this
G'Day
My understanding of uninstalled rating is that it is derived from tests without ancillary equipment and corrected for ideal 100% efficiency intake and sea-level ISA. In other words a situation absolutely unrealisable once the engine is installed and the various bits get connected. It therefore represents an upper bound to performance. Richard Shevell used to say 3% losses were a back-of-cigarette packet figure, then he'd smile and ask what cigarettes you smoked. Gentle and funny man.
I doubt if you can replicate on an aircraft anything like the conditions under which the engine was a) tested and b) then had its figures corrected to an idealised set of rules for the record.
At times I wonder what use unattributed and unqualified figures are but manufacturers have to say something to get the ball rolling. No-one believes that their figures are anything but flattering to themselves.
But the engineers will have the specification tendered against, the agreed method of measurement and company specific implementations. They are best placed to tell you what the real installation losses are, quoting across the fleet and what effect the various mods and chips have.
Best Rgds
the "E"