With the permission of the author, Ian Holmes, I'm including this article on reproductions.  It was originally produced as an eBay guide, but is supplemented here with photos.

'Sunderland lustre' has become the accepted name for all pottery decorated with pink lustre irrespective of its place of manufacture.  During manufacture the applied gold leaf changed to pink. The pink areas should always give a golden lustre, especially on the edges of the pink or where it has been sponged.  Many items listed on ebay as 'Sunderland' were not actually made in Sunderland or even in the North-East of England.  They do however normally date from 1820 to 1870 and are valid antiques. 

Two plaques which have regularly appeared on ebay feature ships called 'FLYING CLOUD BOSTON' and 'AGAMEMNON'.  These were made in about 1980 as Sunderland Lustre reproductions.  They sold for a few pounds and were good as decorative items. However inevitably they have been passed on as genuine antique, the 'too good to be true' price being tempting.

How do we know these are fake?

1 The pink is dull and lacks the lustre effect (see photos below).

2 'FLYING CLOUD BOSTON' was never used by Sunderland potteries (the name does appear on items by other potteries but very unlike the repro).

3 'Agamemnon in a Storm' is a genuine 19th century transfer showing an almost capsized ship, BUT simply AGAMEMNON was never used and the ship shown is not in distress (see footnotes below).

4 The plaques are undersized and lack well-defined moulded borders.

5 The crazing is too perfect.

6 You  will probably never see a damaged or restored AGAMEMNON or FLYING CLOUD BOSTON plaque (because they are so new and also if broken not worth restoring).

7. They often appear together as a pair - in shops or on ebay usually with no other genuine Sunderland lustre items

A genuine transfer titled 'Agamemnon 91 Guns' is known to exist on jugs (see below left), but it is very different, and to the author's knowledge was never used on plaques. The centre photo shows 'The Agamemnon in a Storm' referred to in the text above.  The right picture shows the source for the reproduction transfer, from the Illustrated London News, which actually depicts the Australian clipper ship 'Marco Polo'.  19th century plaques were made using this image (see common ships) but are easily distinguishable from reproductions, because they aren't titled.

The plaque below is a double whammy, being both a reproduction and over-painted.  See the Over-painted items page for more examples of plaques with faked enamels.

The plaque (top left) is only recognisable as a reproduction because it bears the Adams crown mark (top centre), as does the farmer's verse cup.  It was used at their Greenfield site 1914–1955, and at their Greengates site 1914–1970. There is nothing similar to the plaque in Furniss, Wagner and Wagner's book on 'Adams Ceramics', but there is a lustre jug with a print of the 'Shipwright's Arms' and 'Ship Caroline' (p231) with a similarly large suggested date span (1917–1970). The bowl above has the 'Ship Caroline' on the inside and the 'Shipwright's Arms' on the side.  The octagonal plate has the 'Ship Carloline'.  The printed mark on the reverse is shown beside it.

These 1930's objects from Gray's pottery are usually clearly marked, and have distinctive deep lustre borders (lustre like this never appears on 19th century items).  Despite being 20th century, they are good decorative items and collectable in their own right.  See here for a fabulous Gray's website.

This item has, according to the Maling Collectors' Society, 'a typical Maling castle mark used from the 1920s through to the factory's closure in 1963. Several variations exist, and the words "Estd 1762", "'Newcastle-on-Tyne", or "Made in England" may or may not accompany the castle'.  Without the mark, it would be difficult to distinguish the item from a 19th century original.