Sibelius XML drum import

Hi I recently received music that was written in sibelius and exported for me(Musescore) to xml.
The import worked remarkably well and out of the 14 instruments only the drums failed.
Its not playing drums but piano.
The visual looks correct. As in the staff looks like a drum staff.
Staff properties look ok.
But when I check Edit/Instruments
Drums Set is indicating it is a Treble clef -Standard, instead of the expected percussion -Perc. 5 lines.

I tried editing the stave Properties, changed instrument to >Unpitched percussion >Drumset. that got me whistles n burps but no drums and if I try to edit the drumpart its not producing the Edit drumset palette.

I tried copying the staff notes to a newly created Percussion staff , same sounds but at least now when I hit note edit, the drum set palette appears.

Saved as mscz and re opened, just in case. No difference, but it does load much quicker.
Shift Selected a section of bars and saved selection (so it was easier to work with) and things went real weird on reopening the selected file.
The bass guitar cleff changed to a treble cleff.
The bass piano cliff was similarly a treble cleff.
I changed the treble cleffs to a bass cleffs and that fixed that.
It was then I noticed the drums were doing a similar thing it was as if the pitch was shifted up too far.

I tried transposing and copying notes to percussion staves in various different ways and seem to get close but still not quite sure its correct.

Unfortunately I don't know the music well enough or musescore to fathom whats gone wrong.
It could be a simple shift it by ?? or nup its broke mate too much work involved to fix it?