The technology to produce a "copy" of the T-34 was certainly beyond the British and the French, and possibly beyond the US to start with. The T-34 used lot of welding and casting in production, which the Russians had developed in their 5-year plans. Britain had very little experience with either, leading to the continued use of riveting even in the Cromwell. The Matilda II used a lot of large castings which hampered production, compared to, say, the Valentine, which was very easy to make.

Jumbo

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"Capital! We're nearly out of ammunition! Now we can get at them with the bayonet!" General Paddy Gough, 1st Sikh War