Sound aside, why did you not replace the VF14 with another one?
I am sure you are aware of the fact that the collectible value of the U47 is affected in direct proportion to the parts that would need to be acquired to make the mic all-original again.
With other words: this mic is now worth the exact amount less on the open market that it would cost to buy a well-working VF14. (Can someone with good English language skills make this last sentence more elegant?)
Plus, you spent more money for the VF14 solid state work-around.
Why am I so adamant that this is a bad idea? Because such extreme customization is rarely appreciated by potential buyers of a classic like the U47: the pool of potential buyers who would be interested in a mic with an extreme alteration shrinks so much that the price inevitably drops substantially.
And because, despite frequent assurances by owners to "never sell this mic because I love it so much", this as every other classic mic will of course be offered for sale, sooner or later, sometimes against the best intentions of the owner (illness, financial trouble, new interests, death...)
Typically, substitutions of core parts on a classic mic make more sense when the mic was already butchered to begin with. I.e. the collectible value was already suppressed from the get go.