I must warn you that LET, Letov and Wolfsberg are different, mostly unrelated companies.
Letov is one of the first Czech aircraft factories (Letov=LEtecká TOVárna, Aircraft Factory) from the 1920s, until the war owned by the army. After the war, Letov lost its inedependence and its design team (same for all other nationalized companies) and manufactured few prototypes for the design teams centered at Prague-Letňany, then it was used as sub-factory for the Aero enterprise (then Středočeské strojírny, Central Bohemian Machine Factory) and produced MiG-15s. After that, it only manufactured parts for the other enterprises, flight simulators etc. After the Velvet revolution it was privatized and in 1997 split into several subsdiaries, which beame independent in 1998 after the bankrupcy of the main company. Of those subsidiaries, the main one was Letov Letecká výroba s.r.o. (Letov Aviation Manufacturing JSC) continues parts manufacturing as part of the Latecoere Group. There seems to be no projects or machines designed by this company cited here. For production and stuff:
www.valka.cz
Letov Air a.s., another subsidiary dealing with ultralight machines, was bought out by the Britih designer Alex N. Clark, one of the guys who worked on Britten-Norman Islander. He started negotiating with the Letov in 1992 about development and construction the aforementioned BoxBird, for which he founded Wolfsberg Aircraft Corp. in England and after the financial trouble of his Czech partner he bought Letov Air and renamed it
Wolfsberg Letecká továrna s.r.o. Another partner in this development was another czech light plane manufacturer, Evektor-Aerotechnik. In 2014, when they introduced Wolfsberg Sparrow ML pusher ultralight and it seems that the company changed its owner and also name (to
Wolfsberg Aircraft, s.r.o.).
LET is an old company, founded in 1950 on the premises of secondary factory of the Avia company in Kunovice, Moravia. Its main products were aerotaxis and training planes, so the "old" factories could focus on military production. By the way, in the 1950s it had wonderfully communist name Machine Factory of the First Five-year Plan. this is the company where originated most projects mentioned here. Since 1969 it produced L-410 Turbolet, their only product today. After a many close bancrupcy calls and ownership changes, few years ago they were bought by some Russian company and part of the production is now completed in Yekaterinburg, with fears of transfering all production there. Current name:
Aircraft Industries s.r.o.
Production and stuff:
www.valka.cz
Your first and last post are about the Gryfair "company". that originated in the 1980s as a group of aviation enthusiansts led by Jaroslav Dostál who decided to privately develop an ultralight aicraft. It was built by this guys in the LET Kunovice workshops, where they worked at the time, "serial" production of their Gryf (Griffin) UM-1 run in small firm named TIB and later in their own club,
UL klub Gryf Uherské Hradiště. It seems that they later transformed into this Gryf Aircraft, spol. s r.o. (Gryfair) , which doesn't build anything but develop planes for others.
Skyboy - development of Gryf ULM-1 from 1993, built in series by Interplane sro. Czechia.
MD line - composed of several projects of all-metal ultralight airplanes:
MD1 crossBLADE - low wing, project only
MD2 crossTRAINER - project only
MD3 Rider - shoulder wing, manufactured by Flyitalia srl, later by Next Aircraft
- MD3 Rider SL - without wing struts
- MD3 Rider RG - without struts, retractable gear
MD4 Crossfire - project, low-wing development of Rider SL
MD5 Crossblade - project, higher power, capability to carry a foldable scooters under the wing...
MD6 Corsair - project, simpler MD3
MD7 Skyrider - project, larger MD3
MD9 Metík - study using all that was developed for previous three studies.
Shark - composite UL plane capalble of FAR23, built in series by Shark Aero sro., Czechia.
P27 and P32 are another projects of Dostál, same for L-430, L-450, L-510 and L-420E.
