Affirmative on the spring thing. I also replaced the standard
iron with a LV replacement. It makes very nice wispy shavings on
poplar/cherry/mahogany. Birch is another story, way to much chipout.
Can a #4 stanley bailey, even with a narrow mouth setting, and a
scary sharp blade be expected to handle birch. Is a more refined
technique required ? Speaking of plane colours, I have a blue # 4,
which I guess isn't very old and a wine coloured # 4 which has no
adjustment screw on the frog. I wonder when and why Stanley made a #4
with no frog adjustment screw??.