DSP / LSPV for Japanese built SJ410?

[J9V6]

Hi,

I have a 1985 Japanese built SJ410V that is in need of a replacement DSP / LSPV. The part number according the SJ410 parts catalogue is 51950-83120. I can't find these anywhere online, so thought I'd ask here to see if anyone has one, knows a supplier with one gathering dust on a shelf or of an alternative which can be installed in the same location (on the chassis in front of the rear wheels and not on the rear axel).

Here's the parts catalogue image and part no:

Thanks for any help,

Al.