The terms Unfinished and Trial are purely Fieldings terminology.
I think the term Unfinished applies to pieces that are clearly broken pieces like a vase which has been cut down and ground. Then there are Perfume Bottles which have not got their stoppers.
As for the term Trial you would have to ask Fieldings.
Richard is notoriously lazy at signing his work. His thinking is and I quote 'You can see if its made by me' In all the years I have dealt with Richard I have always got him to sign fully all his pieces and to include the word Trial if applicable.
I am almost certain the person who was to blame for these forged signature pieces knows that we know who it is and has stopped putting pieces out to auction on Ebay and home counties Auction Houses. Richard is one of the nicest people I have ever known and its alien to Richard that anyone would want to do this.
I do feel that Auction Houses have a part to play in all of this by actioning 'Due Diligence' on any of the items they sell.
I know they sell thousands of pieces in a sale but that is their job and as far as I can see they are only doing part of it, selling and taking the money. How many times have you seen an auction catalogue 'Signed and dated' on a lot. Well what good is that? Its just that little bit harder to actually put down what the sig and date is. Its just pure laziness and cant be bothered.
I think the same as you with regard to posting of Fake & Genuine signatures which is why I haven't as yet published them. I am of the thought that it is still very difficult even when you know how a piece is signed to actually do it and the people that commit this crime aren't that great at the detail. Its still up for more thought before I publish anything on this subject.
One last thing 'BUYER BEWARE'