Calibre nos required

I have a gents Vacheron Constantin with the following ref numbers on the back plate,PB454/5B, 490862, can you give me any info about this movement, and if parts are still available? 
                                                                            Thankyou Alan Johns [Jeweller]

Cal 454 was one of the basic manual cal used by VC from
09/03/2008 - 19:26
the 40s  Here's something which may interest you click here to see the post You can also use the search function to see the different topics on this wonderful cal. VC still has parts but they will not deliver it outside. You will need to send your watch directly to VC to have its parts completed or changed.