.... always the possibility of one or two in shed collection along with various other classic makes, secreted away for decades; a tight lipped collector of all makes n brands, n with the generational shift to everything in a digital non physical world, chances of these long held treasures being unearthed by offspring, who then have a quandry about finding a sympathetic yet monied up buyer, if it's Irish reg, perhaps wishing it stays on these shores ....
....if I was laying out Split money for an Irish Regd split window, put it this way, I'd want to make sure it is an actual original Irish split window that's somehow survived - you'd need - either in yourself or someone on here/or elsewhere, who does actually know the vast encyclopedic knowledge of splits in general - where the numbers are n the door/decklid/hood/inner pressings n all the timeline changes stuff year to year if yr handing over the sums that any RHD split rear window beetle commands these days.... Not something yed want to rush into it mentally sell bk to yourself the idea that the opportunity has to be jumped on immediately n all that ....
Anyways best of luck with the search