I look at it as "get what works, till you can find what's 'right' ".
If it's any consolation, C2/L2 parts are no less difficult to find here in the States. Most (all?) of the unique parts were made by Long Branch in Canada, and they shut down for good in 1976...the Canadian MGs all went in the shredder (though spare parts came to the US), and only well-used Kiwi/Malayan L2s made it here as parts kits. If the Aussies made any of the LMG-specific parts themselves, I've never heard of it. I bought my L2 for a bit over $3000...somebody was recently advertising the unique parts on GB for nearly as much. Guess I'll never get a proper rear-sight top cover for mine....