That is the correct Vandervell part number for the rod bearings. Unfortunately there doesn't seem to be anyone who stocks them on a regular basis. The best bet appears to be eBay - Italy, which is where I found my last set.
Do you happen to need new sleeves? When I rebuilt the motor in SL*0200* I had Darton Sleeves make a new sleeve for the damaged cylinder. It was expensive but a beautiful piece and any 1400-based motor that I rebuild again will get a complete new set. The difference between the Darton product and the original is night-and-day in terms of quality. They have the pattern in stock so the wait shouldn't be too long either. No commercial connection, just a very satisfied customer.