As only two of the original K&C Horsas were ever made (one of which resides permanently in my collection), and at least one, possibly two were produced with the improved clear canopy a couple of years ago (one of which resides permanently in the collection of a friend of mine who would never sell), I would be very skeptical of any claims that a K&C Horsa is for sale - there are only one classic and one new unaccounted for.
The early Spitfire MK1, on the other hand, was one of the more heavily produced K&C Warbirds, with as many as 150 made, and they do come up for sale occasionally. They often had "LO" squadron markings (I have seen K&C Spits marked as LO-Q, LO-J and LO-D).
As to the claim that the Horsa was made in the same factory K&C used for the classic warbirds, it is possible. K&C used three different Philippine factories back then (with different finishes [some glossy, some matt], levels of detail, and even sizes of the planes [some were closer to to 1:30 than 1:32]). However, as there are literally dozens of factories in the Philippines producing these models, it is unlikely.