Intercompany SI SK OK PV Traceability

Is there anyone who knows how to start at a PV number and trace all the way back to the original SI number? I can figure this out if I start from the OK, but not from the PV. So even if someone can just show me how the PV references the OK or vice-versa, then I can take it from ther.
Thanks!!

You can do this via F43121 receipts table..

KCO, DCT, DOC in F0411 -> KCO, DCT, DOC in F43121. You get KCOO, DCTO, DOCO, LNID (OK purchase order)

KCOO, DCTO, DOCO, LNID in F43121 -> KCOO, DCTO, DOCO, LNID in F4311. You get RKCO, RDCT, RORN (related SK)

Just what the doctor ordered. Thanks very much!!