Lloyd3, first thing is to verify that the model is in fact a Crass. Many of the serial number tables are incorrect and list the Crass much later than the 55000 mark where the Lewis starts. If indeed a Crass, there were three distinct frame styles and several different barrel extensions. Also upland guns and waterfowl guns had different dimensions across the breechface. Lots of differences to consider, but I would not look at it as an impossible task.
The Lewis model has a top lever fastener as well as an underlug bolt.
Buttstock inletting is different on each of them also.
John
Last edited by John E; 10/08/20 12:26 PM.
