Nostalrius Begins - Quality wow vanilla realm (1.12)

http://www.wowhead.com/item=3475/cloak-of-flames
or
http://db.vanillagaming.org/?item=3475
The Cloak of Flames's damage shield effect used to benefit from spell damage ( on retail Vanilla) but here it does not! ( it has Immolation mechanic according to wowhead).
I've tested it with Arcane Elixir + Elixir of Greater Firepower + fire spell damage head ( + 39) and healing/damage gloves ( + 12) with a total amount of 100+ spd. But the damage shield value was still 5.
P.S. Essence of the Pure Flame ( http://db.vanillagaming.org/?item=18815 ) has pretty much the same effect.

Can someone tell, will the damage shield effect ( of these 2 items) increased by the spell power somehow?

I have no idea, but since you've done some research, you could post it in the bugtracker for the staff to validate.
https://forum.nostalrius.org/viewtopic.php?f=45&t=17067

I wouldn't really call this research. Do some actual research and find out exactly what it used to do in what patch and when it was nerfed and why. (small tip, it was 'reduced' in patch 1.2(don't know what they mean with reduced))