Whilst browsing eBay today I came across this unusual lot. It has 5 days to finish and to date has no bids on it.
The lot is described as - 1970 high values definitive first day cover - Official Arnold Machin signed - and rare. Issued on the 17th June 1970 for the official Arnold Machin OBE Patron of Staffordshire Society for Mentally Handicapped Children.
It also states that only 100 covers were produced to raise funds . It is signed on the front by the by the great man him self, the number on the reverse is 80.
More information from the seller states it is a rare FDC which does not seem to be listed and has a printed letter inside informing people that these covers originally sold for £10 each.
Information that is not given in the write up - looking at the picture supplied it is also addressed to Arnold Machin Esq.
The starting price is £14.99 with £1 postage. I personally think this is a nice collectors item, but as I do not collect covers will not be bidding on it. If you fancy a dabble on this, here is a direct link to the offer