Don't worry. There are numerous businesses in the EU that can supply You with a subframe. Some more expensive than the others. Replacing the subframe is quite a simple job actually if You have the tools and the facility. Prices for a bare subframe vary between 1500£ to around 300£. They are available from the U.S. as well, Lithuania, Estonia, Netherlands, even from the U.K.
If Your car failed the MoT then You need to find a replacement subframe. As You know the subframe is not 'supposed' to be repaired/welded, hence many scrap the complete car, which is so wrong...... (The subframe should ALWAYS be inspected before going to the MoT. After a failure You need to find a good replacement subframe).
Search the internet. You will find one..... or three....... part number XR813273 is superceded by three more numbers, but start with that original part number.
BR, vp