In order to quickly repair the XM-X1 Crossbone Gundam X-1 Kai Kai "Skull Heart", SNRI made use of spare parts leftover from Tobia Arronax's XM-X3 Crossbone Gundam X-3. It should be noted, the three original Crossbone Gundams were not three distinct units but rather three minor variations of the same base mobile suit. As a result, X-3's spare parts could be applied to X-1 with no trouble at all.
To keep a mobile suit in working order, three units' worth of spare parts are needed; thus, SNRI kept many spare parts for the X-3 in storage following the Jovian War. However, as the technology involved (especially the downsized I-field generator) was top secret, SNRI hid these spare parts even from the Crossbone Vanguard, only bringing them out when it was absolutely necessary. The "Patchwork" can also equip the hook shield, a Federation technology used mainly to collect space debris; because it needs to be able to resist strong impacts, it also functions as a very sturdy solid shield.