The book states that there are indication of at least one example that were issued to JG11. This particular aircraft was also equipped with the EZ42 gyrostabilized sight. It would have supposedly been in JG11 for the last couple weeks but without official papers (everything was chaos at this point) it is very difficult to prove with hard evidence which can't be found. Also there are photographs of what some claim to be 152C fuselages, and witness reports of 152C airframes being scrapped but again, no hard evidence. The timeline is right for one of the planned production plants to have started production just a few weeks before end of hostilities, I do not recall which one off the top of my head, so there may have been a batch of 152Cs that saw service after all. Nobody has been able to find compelling evidence of that actually being the case so the official stance remain that, probably not.
At the time the allies often failed to distinguish between the different langnase doras, they all looked very similar and the priority was to get rid of all the "nazi junk". It seems the allies failed to recognize the 152C at all, and they picked a few 190D and 152H models to be shipped to the states for evaluation. This would explain why there are no allied findings of the type post-war.
Edit: Also any combat encounters with the Ta152C or 190D would be classed as 'longnose doras' or 'longnose 190s' as there was virtually no visual difference between the two. Heck the 152H was identified as 109s by a 3-ship Tempest formation in one encounter. So it's all very sketchy.