Even if the armor is a specialty alloy, the troups have been beefing up their Humvees with "scrap steel" from the dump. I cannot believe that a "temporary" armor could not have been produced with run of the mill steel plate that is readily available.
I have a strong suspicion that we are going to find some damn bureaucratic reason why we had to wait for the manufacturer to do the reinforcing.
There's little question that Pentagon specifications have something to do with it--not to mention the Pentagon procurement process (qualification of the vendor, does he/she/it have EEO, etc.)
Remember that Bob McNamara personally intervened in the design of the M-16, which made the weapon damn near inoperable in the field...