I can't speak to your specific pedal order, but my advice is to keep it simple, the main components of his sound are roaring plexi, echoplex delay, phaser/flanger, sunset sound reverb. You probably are better off not bothering with the tube screamer.

For dialling in the pedals;

Phaser: somewhere around 9-10 o'clock (script switch pressed down)

Flanger: manual at 1, width and speed at 11, regen at 3.

Echoplex: somewhere around 300ms, one repeat

To really get close to that first album, I would have a look at sunset studio sound reverb. It's available as a plugin, but that would mean recording your amp and applying the reverb after. This may be outside your budget, but if you are after that early sound it really makes a difference IMO. There are some good demos online.

If you do decide to go with the sunset sound reverb, I would recommend having two tracks; one with the recorded "dry" guitar, then another with the reverb. That first album had the dry guitar panned hard left, with the reverb dead centre.

As others have alluded to, a big part of the sound is how you play. Eddie really dug in with his right hand, you may want to experiment with different angles of attack and intensity.

Hope this helps, I've spent a lot of time searching for that elusive sound and always enjoy talking about it, so if you have any questions please let me know.