A1 intro date is Apr, 1922 and retire date is Dec, 1959.
A3 intro date is Oct, 1927 and retire date is Jan, 1966
A1/A3 tender intro date is Aug, 1922 and retire date is Jan, 1952
A4 intro date is Apr, 1935, however A4's specific carriage set, Coronation, has a scattered intro and retire date. Some parts are available from Jan, 1935 until Jan, 1955 while other parts are available from Jul, 1935 to Oct, 1955.
The game, in the depot window adds constrained pieces automatically, even if they are not introduced yet, but in the 'replace' window, these will not show up.
Thank you for pointing out those anomalies - they will be fixed in the next version.