Are the wagons always under-sprung? Any sort of leaf swap is going to change the rate of the spring. I know that they have probably lost some of their set and now the car sits lower than it did originally. I don't see that as a bad thing. Cars of the era were usually designed at one ride height, and then actually sold at up to 2" higher due to snow chains & road irregularities concerns.

Absolutely concur with fresh front end equaling increased confidence in the car.

I also think that to some degree you have to accept that you're spend money on parts that you may not use very long if driving the car during the repair/refurbishment/upgrade process is desired or necessary. Of course try to plan so that you don't, but accept that it's probably going to happen and work to minimize it.