I never had any issues servicing any UN watches ranging from simple GMTs to perpetuals to split second chronographs. Claret is still around and the parts can be supplied. I would argue that it is easier find or manufacture a part for relatively modern repeater, than for Venus split seconds movement
First of all, I believe all UN repeaters and strikers are jacquemarts, which makes them very interesting and unique. There are two types of UN chiming watches (not counting the Sonata): half hour strikers and real repeaters. Hour hour strikers appeared in UN catalogue in mid nineties I believe. They
I bought my monopusher at the time when the watch straps were not something ADs charged for. So my Cartier dealer just added bunch of straps to the watch in case I want to change the look. I still have them all.
I like manual movement and its finishing of the current model, but in my opinion toubrillon opening is disproportionally small comparing to case size. Plus the dial of the new one looks a bit austere to me, comparing to amazing guilloche of the original.
My bank still offers them, but in fewer branches. Safe deposit boxes are also getting smaller: I used to keep two perpetuals on Sempre winders inside the box, but right now the one I have barely fits two watch rolls. It is also important to keep it mind, that the bank is in general not liable for it
In over 30 years of watch collection only twice: a lady at the grocery store register thought that my UN Jungle repeater is a Disney watch and few years ago a gentleman recognized and commented on my UN Aqua perpetual. Other than that no one ever notices my watches.
If you know the year when the watch stopped, it is easy to estimate. If you don't, you either send it to manufacturer or risk pressing correctors thousand times to land on the correct year