In fairness to the Brits, it would have been unfeasible to find all the Lithgows still in service and return those specifically, plus after wastage, they could never have returned the proper number.
I also doubt they selected worn rifles specifically. Many MANY of the SMLE's in inventory had spent a long hard war shooting cordite and being dragged in the mud. The AEF rifles, for that matter, largely needed rebuilding.
Personally, I like the lithgow-rebuilt Brit rifles - they have an interesting history.