And here is the rest of the story...
PureBlood offered to send me the SKS gas tube I was looking for - at first he asked that I pay for postage.
But then he just sent it to me entirely free of charge. And it was in immaculate condition. So I asked him if there was anything he needed. I have a bunch of extra FAL, AK, and AR parts lying around.
He asked me if I could send him a specific barrel clamp optics mount. He sent me a link, stating that it was out of stock. But when I checked the link it showed that it was in stock (probably something about the website geo-locating). So I ordered three and (after an adventure in modern logistics) got three of the parts he wanted and shipped them to him. So, because he offered to send me something I had been looking for more than ten years I not only got what I needed but was able to help him get something he couldn't get where he is.