MG T-ABC

I am the care taker of TC 5061 since 1969. The previous owner had a TA in parts and therefore I detected a few TA parts on this TC. I recently lost my fuel tank cap (pricey) and found out that the hinge pin that this cap is connected to suppose to be a split pin on TC's. On this TC it has a narrow long bolt that apparently vibrated loose, hence the loss of the cap.
My question is to any TA owner that reads this: Do I have a TA petrol tank??? I can drill the screw thread out install a regular TC split pin, but I just would like to know...

Thanks,

Josh

The TA tank will have an extra fitting on the bottom for the reserve line. If you have only two fittings - one for fuel line and one for drain - then it's a TC tank.

Here is the cap on my TA tank.
The entire cap unscrews to remove it. and here are the 3 ports or fittings on the bottom.
main feed, reserve feed and drain There is no level sensor.

Quite a bit different than the TC. Late TC. Split pin is not original.