Baffle -oil -- for MGA 1500 gearbox -
- Com.(G)A1861. Fin.(G)MA8010.
This part was only used for a range of 6250 gearboxes during the production of 1500 model cars. Not used in Twin Cams, and not used in 1600's. Since it was only use in 6.25% of all MGA, I recon it would be a safe bet to remove it and forget about it. The part is (naturally) No Longer Available as a replacement part.

This is obviously a shield for the back side of the front ball bearing, installed as a separate part (not originally part of the bearing). The two inner folded fingers should (I think) clip onto the OD of the inner bearing race long enough to get the 1st motion shaft assembled. Then it will be (loosely) trapped between the bearing and the face of the input gear, and should rotate with the inner race and the shaft (while the outer bearing race stands still). So if it was bent to touch the outer race it would make a slight scraping noise, but likely cause no harm.

I suppose removing this shield would require removing the big nut and the press fit bearing (difficult without a proper bearing puller). If bent, you should try tapping it flat as possible, giving preference to touching the input gear face and not the bearing outer race or the face of the laygear.