PC50UU-1 Track/Undercarriage Types — Questions on Rubber Tracks

[TerrainTamer]

Hi all,
I’m looking at a PC50UU-1, almost certainly a grey-market machine, with a serial number around 15xx. It’s fitted with rubber tracks, but I have some doubts that they are the correct ones for this model. Observations:

• The tracks don’t sit well in the load rollers.
• The idlers show flat spots and bending, which suggests they’ve been over-tensioned. I suspect the idler radius is too small for the length of these links.
• The tracks have 36 links, but most (unverified) specs I’ve found mention that they should be 70 links.
• The tracks only engage every second tooth on the sprocket.

The sprocket has 19 teeth — is that the correct count for this model? I can find listings for 19t sprockets for this model. Does anyone know the pitch?

I’m torn between this being a correct setup for an early serial number machine (except tracks), OR some kind of grey-market peculiarity.

Does anyone have parts information relevant to the early PC50UU-1 undercarriage or track types?
Many thanks