OK, I guess I should have started from the top. All TQG's have the same air cleaner. So you should be able to get a top from someone with a junk gen set. From MEP-802A all the way to MEP-806A, they are all the same.
Now, I was looking at an OLDER parts manual, when I gave you this info in message #2. Doesn't matter. We were looking at the same info, just different format. In message #2., I gave you a NSN and part number. P11-9711. That number was the same as the one you looked at in your parts manual. In your message, you wrote, P11-9711 COVER,FLUID FILTER.
Same number. I had more info, (NSN) because I looked in the back of my manual, in the section that changes the manufactures part number over to a NSN. Sadly, your manual doesn't have the information, or you didnt know to look it up. BUT, now you know, and can look in another manual, (for instance the MEP-805A) for that same part and PART NUMBER. It has to be the same. Not close. The same. And most other manuals have an NSN in the parts explosion picture, or in the back of the book, where you can crossover the part number to NSN.
The next bit of info I had, that you didnt have is WHO made it. When you want to know who made it, look at the CAGE CODE. And you did have that in your manual. 18265 P11-9711 COVER,FLUID FILTER
18265 is the "codename" for the manufacture. Every company that supplies parts to the military has a CAGE CODE. How do you get the name of the company from the cage code? Well, as much as I hate to say it, GOOGLE IT. Simply write CAGE CODE 18265. It will come right up. The address you should be able to find easy.
Now I have a question for you. What manual are you using? Did you download it from SS? If not, then compare your manual to the one in SS and make sure that the manual you are using has the latest date, and then look to see if it has the latest update/change.
Another tip. When trying to find a part in flebay, or when you look in your browser, ALWAYS, if you can, include the NSN. You will have much better luck finding a part.