When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Perhaps you need to clarify your question. Please remember that the original manufacturer is no longer in business and thus by definition any subframe available today is aftermarket. "British Motor Heritage" product is as close to original that you will find but in fact is still a copy. Over the years we have seen (and used) a number of different companies offer subframes and have never heard (or seen) of one that had any sort of fitment issues.