After the 1960s he appeared to return to obscurity, apparently having spent all his money. He died in 2000, aged 73.
This blog was prompted by the purchase of a couple of his albums in a local charity shop (actually they give away their records for a small donation - as much as you can carry!). They seem to hold up a decent price on eBay, all on vinyl too; were they not released on CD?
Here is a documentary about him from 1967.....