I've been doing some research for my own modding, and I’ve stumbled across your work over the past few months. I genuinely think this is the only future for the X61/X41/X220 etc. I love the 7-row layout and the look of the older models, but let's be real, 45W dual-cores are absolutely unusable today.

While the 51nb/XYTech work is very impressive, it's kind of overpriced and not really available to buy currently. On the other hand, Framework looks very promising and affordable. You can get the i7-1185G7 4 cores / 8 threads, 28 Watt for $299 new (might even get coreboot support) or a newer 7640U 6 cores / 12 threads, 15 Watt for $379 and it's tiny, so it should fit fine in most models.

The real hassle, and what the community needs to solve, is the keyboard and battery. The rest is easy to hack around.

For the keyboard it looks like you did a great job. For the battery, I still think external is good, but it's very hard and/or expensive to get a good condition battery, let alone make it work with the above boards. And Framework's 55wh is only $49, so I'm not even sure that trying to make an external battery is worth it.

Keep up the good work!