I am sorry if you felt ignored on this site. I certainly would have offered advice if I had a 240 (which I don't), had a station wagon (which I don't) and had a similar experience (which I haven't). If a broken rear seat latch is the only serious problem you have had with your 240 wagon, consider yourself extremely fortunate.
This site can be a great place to both ask for advice on issues and also to relate experiences from which you have learned and can share with others. I don't want you to think that I consider anyone's problem any less important than anyone else's. But a broken rear seat latch is a very rare occurrance, which doesn't effect the drivability of the car, and if experienced by any of the many "shade-tree mechanics" out there, was probably delt with immediately, with very little challenge. The fact that you didn't receive any replies to your post tells me that the readers of this forum out there probably didn't have any experience or useful advice that they could give.
Posting a question on a forum doesn't guarantee you will get an answer. I behalf of a friend, I posted a question on the S80 forum back in July. No one ever responded to that question either. But I attribute that to the fact that the S80's are much newer vehicles and rather expensive to purchase. Most people who have the money to own one of those cars most likely pays others to work on their cars for them and couldn't be bothered with getting there hand's dirty. Therefore, there was no one out there with any real life experience who could or would respond with a useful reply.
I suggest that you don't give up on this forum so soon. One day, your car may present to you a problem that could have you and your mechanic stumped. This is the best place to come in those situations. The advice here is much cheaper than paying a mechanic to learn about it at your expense.
Chris the "K MANIAC"
1986 740 GLE
(5) 1964 Chrysler 300-K's