MC2 Racing are out of stock with the poly diff mount (anodised blue). Got that reply yesterday from them about it :

"I'm fairly certain that I just sold my last polyurethane diff mount this morning. I do have more on order, but they will take a few weeks to machine and another couple weeks for welding. You're welcome to purchase a diff mount, but please understand that it will take a long time before it ships. Ordering now does ensure that your diff mount will ship immediately once they're available."