Class 108 railcars were introduced in 1959 and were an improved version of the very first lightweight units which first made an appearance in 1954. Unlike the earlier cars they were fitted with steel cabs of what had become the standard Derby Works design. Six batches were produced and 56223 is from the fifth batch of  50 two-car sets which were built for the London Midland Region. There are several differences between this and the other 108 trailer in the fleet, 54490, particularly regarding the front end arrangement, which does not have the four-character headcode blinds.
 
This vehicle was allocated new to Llandudno Junction Shed (6G) but moved on to Bletchley (1E) in 1960 and again to Chester (6A) in 1966 and Longsight(Manchester) in 1968.
It ended its career at Old Oak Common Shed, near London, in June 1993 and passed into preservation. It was then kept at Southall under the care of the GWR Preservation Group until November 1997 and when their centre closed, it was bought by DUPA and moved (by rail) to the East Anglia Railway Museum. In March 2000 it was off on its travels again, this time to the North of Scotland, where it was used at the Keith and Dufftown Railway until 2005, when it was again returned to East Anglia.
It then lost its Network South East colours in 2007 and was repainted in British Railways light green, though it kept its late-BR headlight arrangement. It was  used from time to time on the museum's demonstration line but was offered for loan when it became apparent that Llangollen Railcars would be short of vehicles while the Cravens 56456 was being rebuilt.
The vehicle moved from East Anglia to Llangollen in early 2010 where it received a full cab refurbishment, electrical repairs, some ceiling panels and a heavy exam before being introducted into service for a charity event for one day in May. This was earlier than anticpiated as the official launch was at the June Railcar Gala.