Rumor has it you can get a new lower timing belt cover, MK2 style from thebusdepot.
The upper cover survives and you can probably find a MK2 upper cover quite easily.
A lower MK1 cover is almost impossible to find.
So many have been torn up by pullys.
Not sure what kind of mounts you have in that area so can't tell you what cover to use.
The MK1 has a relief for the mount on that end of the engine.
The MK2 put the mount behind the engine.