Replacing movement: Proper or not

[joelcarvajal]

Hi!

Background: I was approached by a young teenager asking me to repair her grandmother’s watch.  It’s a Seiko ladies watch with a 4206a movement and a lot of sentimental value.

Issue: I think many of you will agree how problematic this movement is.  In this particular case, the metal bushing of the 3rd wheel is worn out.  I have the option of replacing the bushing with one from a donor movement; or I can replace the entire plate or even the entire movement with another 4206a.

But will it be better to replace the movement with a refurbished 4206b (the improved version) or even a new NH05(?) movement?  We can argue that it will significantly extend the watch’s life.

I can of course explain these options to the girl but in general, our clients will just usually say, “do what you think is best.”

So here’s my question:

Apart from replacing mainsprings and broken parts, most watchmakers try to keep the watches they repair as stock as possible especially if the watch has value, sentimental or monetary-wise.  As such, replacing an entire movement may not be the way to go.  Some may argue that replacing the movement makes the watch different altogether.

What’s the acceptable practice here?

Assuming cost is not an issue.

 

Edited March 18 by joelcarvajal

[HectorLooi]

Ladies watches are so tiny that working on them can be a real challenge.

If it were a men's watch, I would rebush or replace the bush with a jewel. 

There are a few 4206a main plates available on eBay. I would probably replace the mainplate.

I don't think the customer would mind replacing the movement with the exact movement. Just don't replace it with some cheap Chinese movement or God forbid, a $2 quartz movement. 

[AndyGSi]

I agree with @HectorLooi that the first course of action would be to replace the plate.

Failing that it would be another 4206 movement of some variant but nothing else.

[caseback]

Why not (providing that's the only issue) just replace the worn bush with a jewel?

[AndyGSi]

39 minutes ago, caseback said:

Why not (providing that's the only issue) just replace the worn bush with a jewel?

I think the major issue would be cost with no overall gain in the outcome.