Hybrid classes, using parent class items

Can a Hybrid class use a magical item that is specific to one of it's parent classes. As a specific example, can a Skald, use the Resplendent Robes of the Thespian, and gain the SR, Save bonus and Spell Pen boost?

Nope. A skald is not a bard. Mechanically pretty much the only meaning of the term 'parent class' is that if you have a similar ability from a hybrid and a parent class where you have to make a one time choice (like a sorcerer and bloodrager bloodline) you have to make the same choice for both if you take both classes.

Unfortunately, I don't see a rule that would allow this (apart from simply crafting a skald-friendly version with GM approval). The brawler class write-up has a specific class feature that allows the brawler to count as a fighter or a monk for the purposes of magic items, but the skald has no similar verbiage.

Yep. Exactly as I assumed. I have Skald player who was hoping. I don't allow any custom crafting, so he'll have to just replace the item.

Yeah, it's a bit of a letdown, for instance, that Hexing Runes
Corset of Dire Witchcraft & Cackling Hag's Blouse can't be used by: Shaman, Hexcrafter, Spirit Whisper, Sylvan Trickster, etc.

Here is the relevant FAQ confirming what everyone has said.

Bloodrager Bloodlines: Can a bloodrager use abilities that require sorcerer levels and relate to sorcerer bloodlines like robe of arcane heritage?
No. Some hybrid classes, like the brawler, have a class feature allowing them to use items related to their parent class, but the bloodrager doesn’t.