I too want to add my congratulations on making an excellent model from a not very promising kit. Like you I value these old Airfix kits (and not just for sentimental reasons although I too remember building them a long time ago), because as you correctly say, they are the only ones on the market in God's Own Scale. I too would like to see this re-tooled but I am not holding my breath, so I may have to follow your excellent build thread and give it a go at some time in the future.
Your comments about the Royal Aircraft Factory are well balanced and apposite - it was not just the Factory which was to blame, although those who opposed government involvement in aircraft production and design tried to use the Factory as a whipping boy in support of their prejudices - but also the procurement processes of the RFC in the early months of WW1. The RAF actually produced some very advanced designs for the time - the problem was that British industry did not have the skilled labour or equipment to manufacture those designs quickly enough so that they were often obsolete by the time they reached the front, and were kept in service for too long while other designs were brought into production. Chronic shortages of suitable engines was another problem that took a long time to resolve. Private aircraft manufacturers were also slow to rise to the challenge of the fighting conditions and had a very steep learning curve to climb. As usual the actual history is rather different from many popular myths of the period.