The only thing that shows up when you Google "Maleficos Inheritance Accelerator" is references to the Clarecraft figure. This makes me more convinced that it's not actually mentioned in any of the books. But I could be wrong. Sorry we couldn't be more helpful.
Its ok. still a cool item either way. Will see what the tent card says when the one I won on ebay arrives. It will take pride of place next to my luggage figure.
Like the other two potion bottles (Hilda Goatfinder's Diabolica for Men and Granny Weatherwax's Invigoratore and Passion Philtre) this is a Clarecraft specific item and doesn't reference any of the books other than it could easily be believed that it would exist on Discworld
A quick google tells me it's in Mort - 'Granny Weatherwax's Ramrub Invigoratore and Passion's Philtre, Onne Spoonful Onlie before bed and that Smalle'.
I'm not sure if this is relevant but I was wondering if there was a parody to one of the Discworld books. I mean the parodt to Lord of the Rings is Bored of the Rings (I just read it )...
There are a few pages in one of Tom Holt's books which explicitly parody Discworld, (viewing it through T0om Holt's universe) but this is more an author homage, I think. Wish I could remember which one!
Terry generally doesn't write in chapters at all. There are chapters in Colour of Magic and in his Tiffany books, but that's about it for the Discworld books. I don't think the books suffer at all because of this.
Tom Paulin the critic on Newsnight Review once said of Terry's books:
. . . a complete amateur - doesn't even write in chapters - hasn't a clue.