Well done, Mayfly. I'm glad the project has turned out so well for you. It seems that you got your hands on some great components, but more than that, this is a testament to your assembly and troubleshooting skills, and perseverance. I chuckled a bit to see your temporary component testing boards - because my benchtop has seen the same sort of items. And nice work on the populating of those boards. I could swear that resistors and caps get smaller every year. No, it can't be my eyes getting worse - it's just a coincidence that I keep stepping up the power of my magnifying equipment.
Too bad that cap crapped out on you. Those box types have failed on me before too. And that sort of thing is a real pain to track down, and de-soldering sux, so cudos to you. These days I try, whenever possible, for most caps to stick to high-quality film chicklets. I never use tants or oils (bah, humbug). But I do use polystyrenes for very small signal-chain caps, although you're right that they're really easy to burn. And they're getting miserably hard to source. You wouldn't happen to have the name of a good supplier, would you?