Carb fuel leak question

I just recently removed and cleaned my carbs on my 1982 Seca 550. Everything worked great after reassembling the bike. A few weeks later I developed a fuel leak from the T-fitting that is at the lower-rear area of the carbs between the #2 and #3 carbs. This is the fitting that the fuel line goes to that comes from the fuel petcock.
I removed the carbs and they are in great shape I eliminated any possibility that there is a fuel line or a carb bowl gasket leak. It's coming from the T-fitting. The T-fitting is looser than I would expect but I don't know exactly what it should feel like. It moves pretty easy when I rotate it. It only will leak when the bike is running.
I'm the original owner and have never disassembled the carb pack so the T-fitting is original. My question is, should I be looking for a new T-fitting? It looks like it is made of plastic but am not sure if there is maybe brass underneath the plastic. If that's the case there is probably not a leak due to a crack. If it's not a crack then I'd suspect o-rings failed at the T-fitting to carb connection
Has anyone replaced one of the fittings that may have some advice? My Clymer manual says that I should leave this job to a pro but that's not my style. I am confident that I can do the job, I am just looking for hazards to possibly avoid. The T-fitting is oddly enough available on Amazon. Has anyone used this part? I'm not sure if there are many other choices.
Thanks for any advice or tips you may be able to share.

 

Replace the o-rings. A small nick in the o-rings will cause a leak. Make sure you use some lube when putting them back in.

 

Super Lube-21030 Synthetic Multi-Purpose Grease, 3 Oz. https://www.amazon.com/dp/B000XBH9HI/ref=cm_sw_r_cp_api_i_4VWK0DFTZQCQ8Q6G103B?_encoding=UTF8&psc=1

This is my choice for any oring or seal install