Several conversions;
The Howell, developed during WW1 used the standard magazine
The Reider, a conversion of the No1Mk3 developed in South Africa, used Bren magazines. It never entered production
The Charleton built in New Zealand on Lee Metford rifles,also used Bren mags. (Charleton Motor workshop)
The Charleton using SMLE rifles converted by Electrolux was a refinement
Then there is the British Howard-Francis self loading carbine conversion of a No1Mk3 chambered for the 7.63 mauser pistol cartridge. (protptype only)
About the only conversion of a SMLE that was actualy in production was the Silenced Delisle (unless you count the smoke discharger conversions) If you remember the first Star Wars movie, thats what the JAWAS used to zap R2D2
Actualy got to see the Charleton in the Pattern Room at Nottingham before they moved it to Leeds.