I think it was a normal watch with a leather strap, made in the 1940s then later modified to add the bracelet.

This is probably the movement family:

http://jaeger-lecoultre.org/Caliber-det ... er_408.jpg

Value is going to be mostly that of the gold + the movement value.

This is actually a watch that was made in the 1940s but was then subsequently modified by a jeweler. Most likely to add an integrated gold bracelet.

Can you post photos please?

Everything looks original except the crown which has been replaced. For the price, I have not had one recently, maybe around 2000-2500 USD.

You should see a small split on the ring if it has one. It's typically at 6:00.

Any watchmaker should be able to accommodate this request. The original part is not anything special.

It may be the type that has a silver ring inside the crystal, if that is the case, have it fitted with one of those.

The original glass is round plastic. Any generic crystal will look fine.

I've never seen OEM LeCoultre alarm crystals for sale.

The refinished dial is worth at least 30-40% less than an original dial.

Movement and case are legit, the dial as you noted appears refinished. Looks authentic to me.

I think on both your watches, it may have more of a "jewelry" value than a horological one. In that context, it's hard to value unless we have the weight on the metal and assessment of the quality of the stones on the B&M. I still don't think there is a ton of value there, but you have enough value ...