Had you not said it was lung tisssue I would never have thought it was - and to be honest I have seen much worse.
Also having had a quick chat with the nurses here, I don't think that you are coughing up lung tissue. But the only sure way of finding out what it is would be to have it anaylsed at a laboratory. If your GP has concerns he should be referring you to a consultant.
"Honeycombing" ,which is often used to describe damage found in pulmonary fibrosis, can only be seen by xray or CT scan - it's not seen under mircroscopes.
What you are coughing up is juat as likely to be something much less worrying such as food particles.
Daz - if you haven't alreday done so - why don't you call the BLF Helpline and have a chat with one of the nurses - 03000 030 555 - talk through your diagnosis and symptoms.