Yes both EUOTC and SUOTC wore the Wessex Regiment cap badge on their re-raising in the 1980s before their own cap badges were made.
https://www.britishbadgeforum.com/fo...ctureid=173285
I have not seen anything that the Yeomanry ever wore the infantry cap badge. They wore the old Yeo regt as Sqn badgesthen the black plastic badge.