Level Adjustment for the Half-Golem

We have just been playing a 3.5 remake of die vecna die (we're just converting it on the fly, it hasn't been published or anything).

My friend was playing a half-golem from MM II. Now the thing was insanely powerful, but since it was vecna we really didn't care But what level adjustment do you guys think it should have?

Probably around +4. Their abilities seem OP at first until you realize that their magic immunity means they can never receive any form of magic healing, neither Cure spells nor potions.

And if they aren't constructs, then no repairs either. Meaning any damage that gets past their DR is just going to inevitably chip away at them, bringing them closer to death the deeper into the adventure you get.

They need all that crazy buff just to break even with that fact alone. The only work around I know would be if the DM wasn't doing magic/psionic transparency and then psionic healing could work.