I finally built a frame for the custom hand printed poster I picked up from Lost Art Press. These were hand lettered in Northern Kentucky especially for LAP and were limited in number. I was fortunate enough to lay my hands on one and am very pleased. The frame is 110 year old poplar wood reclaimed from an old farmhouse in Kentucky, splined with walnut from a local farm, hand hewed and shaped. I think it turned out pretty well.
Lesson learned: When cutting the joint for the spline to fit it is best to use a flat grind blade so you get a nice smooth bottom which will prevent any gaps with the spline. I used a regular blade and you can see some very small gaps (see detail) at some of the spline corners; you have to look for them but they are there and I know it.