What's wrong with DND calling the Indian government and asking them to produce 10,000 No4 rifles in 303 - it'll cost a lot less, and the Indians could do the whole thing in less than a year, while they're at it they could order a full suite of spares and we'd be good for another 70 years. Note that the Indian Armoury at Ishapore still produces No4 rifles in 8mm for the home market, so a 308 Lee is a possibility, at a cost that would allow for double the required number of rifles, plus parts.
And I guess they'd do a rail too.