The timing cover with the dipstick is fitted to the Mk4 Zephyr and some of the Scimitars. They also had a front bowl sump. You need the very early Essex to fit these, they are not interchangeable with capri v6 Essex as the oil pump is mounted differently.
You could use a zephyr/transit timing cover on a capri v6 motor but you would need to make your own sump. You could try a man named Ivan Newton in Vic who does Scimitars. There is also a man named Vic who is the local Zephyr guru, I do not have contact details for either, but Vic and Ivan know each other, try the zephyr car clud for a referral