No,i dont think you cant use 36 in 46 assembly, movement wise 36 and 46 are compatible. Individual parts not all. Considering the beat rate of 46 is 21k6 and 36 is 28k8 transplant the balance assembly wont work.
Not to worry, 1680 needs 46 above 36 as the beat rate is too high (gen is 19ksomething 6?), anyways 46 is not expensive and on 1680 you not need any high canon pinions, so any movement will do, probably can be had working for 50usd. Hand sizes are exactly the same.