The production capabilities of the UEPC is largely understated when one considers the quality of their front-line units. For example the KR-14A Kelleg, the UEPC's primer ground unit, suffers many complaints from pilots that it is rather limited for being a 'multi-purpose axel'. Complaints range from the cramped confines of the cockpit, limited visibility of the camera system, and even the fact that the unit cannot raise it's arms more than 90' over its head. The unit also does not adapt to space well, despite being pressed into service as the UEPC marine unit when conducting colony and asteroid investigation missions (as the MN-18 is not suited for full gravity operations).
Though the UEPC has publicly tried to ease these concerns with the D model (improving on the A model), many are unaware that the KR-14 is as ineffective as it is to cut costs and mass-produce the unit for attrition. Largely, the KR-14 is the unit given to most governments that do not have axels as they are cheap to produce and use common components.
However, for the "Core" nations of the UEPC, there exists the fine-tuned KR-19. Unlike the KR-14 the Kellvar was designed as a high-quality multi-purpose Axel designed to defeat other nations' Axels when operating in squadrons. It is truly an all-purpose mecha, better designed to fight on earth in any environment the squadron is deployed into.
The KR-19 is not a secret unit, but dismissed as a failed pre-production type of the KR-14 due to 'cost concerns'. Skeptics and Axel specialists (as well as some governments) believe that units of the KR-19 are reserved in case any of the other nations of the UEPC decide to attempt a breakaway from the dominant World Government. As the KR-19 is clearly superior to the KR-14 in most regards, this theory is not easy to dismiss.
KR-19 models have no space variants, and are largely deployed within Europe. Fighting units mostly operate out of Principal UEPC founding nations, though it is thought three units of these machines operate in the United States under the orders of the Prime Minster to combat 'cowboys' operating out of the American deserts.