Why adopt? Post the NA and if/when the caches get archived place your own. If you want to pay homage to the old caches, add a link to the old archived caches in your cache description. Are they puzzle caches and you want to retain the puzzle?
Thanks again for the advice.
Neither of them are anything special other than a good location to visit, so having them archived for a bit will not put anyone out.
One of the caches has not been found for several months, but it is my target for today. The other constantly has a "NM" tag but the cache is still there, I was there yesterday. I think the problem is with the design of the container allowing rain to enter constantly destroying the logs.
After my search this afternoon I will probably tag them both with a "NA".