This page is a miscellany of everything else I can think of that is worth an inclusion.

The Dragon Sanctuary covers
There were 10 of these to collect via the new (at the time) GCTS scheme, and two of them had Halfpenny stamps used. My examples of these were the ordinary, common Enschede printed stamps, but it was promised that a few covers would have some rarer stamps, so It may be that there are examples with Bath perforated Halfpennies.
The covers were from people sending in stamps for a charity collection to support the Dragon Sanctuary, and consequently the stamps inside the covers could have some very interesting examples. These items rarely come up for sale these days, though they are nominally twice as common as the Damaged in the Post series. Only once have I seen an unopened one for sale.

    
2nd cover                                click to enlarge                            8th cover

Proof sheet
The Halfpenny stamp featured on the Definitives Proof Sheet together with the Penny Patrician and the $5 Brass Bridge triangle.

Waterstones Cover
The Halfpenny stamp was one of these used on the Waterstones promotional cover. I am sure that many put these away thinking they would be worth something in the future, but there must have been so many produced that they still sell for between £5 - £10 10 years on. This is despite the fact that the 20p Cabbage Fields stamp’s only other appearance was as a freebie with an edition of the Stanley Howler Stamp Journal.