This series of six backgeared Lorch lathes was built in three sizes, each being available as either a plain turning machine - without a G in the Model Type - or with "top slide" screwcutting. The three machines were similar in layout but substantially different in detail. The smallest version, the LLRGN, had a centre height of only 65 mm and a between-centres capacity of 215 mm (2.6" x 8.5"). Like all Lorch lathes its headstock spindle was hardened and ran in hard bronze bearings - the bore in this case being was 10 mm and accepted collets with a maximum capacity of 8 mm. The backgear ratio was 1 : 6
The AVRG was substantially larger with a 100 mm (4") centre height and took 280 mm (11") between it's No. 1 Morse taper centres. The collet capacity was more than doubled at 17 mm and the backgear ratio deepened to 1 : 8.
The largest machine of the trio, the BVIRG had a centre height of 120 mm (4.7") was available in two bed lengths of  1000 and 1250 mm (39" and 49"); this gave it the ability to accept work which was either 390 or 640 mm (15.4" or 25.2") long respectively. The backgear ratio fell between the other two lathes at 1 : 7.

Miniature Precision Lathe Model LLRGN 65 mm x 225 mm with a screwcutting feed fitted to the top slide. This was once a common accessory for high-quality plain-turning lathes and saved the complication and expense of a full leadscrew drive.

Largest of the type, the Model BVIRG had a centre height of 120 mm (4.7") was available in two bed lengths of  1000 mm and 1250 mm (39" and 49") with between-centres capacities of 390 mm or 640 mm (15.4" or 25.2") respectively.