Yes Peter I am sure
The different between 33xx and 78XX is the software and the CRT tube.
42XX and 33XX used 2 way com using BL 5000 or BL 7000, 78XX used one way
Actually I updated a LX MK I (type 4207) and fitted the module. Works fine. both using CVBS or RGB inputs via scart
STB-C recording via V 8000 (SW 3.0 or higher) works fine also.
In the LX model one need to get a plastic bracket (in the right side) that was used for the LM Sat buildt in with mac dekoder module. Actualy in the bracket there are place for both the mac module and the STB-Module.
In the MX the STB module must be placed where the old PiP or mac dekoder module was original placed.(in the front on top of the metal frame. See installation manual for the STB module on this site.
Further it also works with the AV 2 expander (the updated version for DVD operation)
Updated software for the module is still availble.