Lee Carbine Identification and stock disc ID

[Alan de Enfield]

Hey guys I have undated Lithgow but the serial number is in the 3500 region (1914)

The Lithgow accounting year was June to July.
Up to End June 1913 Lithgow produced 40 rifles.
From July 1913 to June 1914 Lithgow produced 4,760 rifles.

That would suggest that your rifle No 3500 was made (probably) Q1 / early Q2 1914