Personally I would also suggest adding the octave selection, really very practical
On my VCOs that don’t have it I miss it a lot
R42 must be changed, i don’t remember exactely maybe 2K (i ll searched and come back 
)
EDIT : I found it, between 1K and 4.7K
(By the way, R42 shown there is specified as 220 ohms but it really should be higher; 220R results in too much current through the voltage reference U4, potentially causing bad behavior and possibly damaging U4 permanently. If you used 220R this would be a good time to replace it with something between 1k and 4.7k. For more on this and other mods see 1222 Tuner VCO Module - #203 by antoine.pasde2 and 1222 Tuner VCO Module fixes/improvements - #6 by eric .)