Paul,
I have a 1986 38 and the initial appearance is very similiar. I have never been on a 39, but owned a 32 before and will provide general potential non boat specific things that see,m to potentially effect the Ericson brand. You will get more detailed information from Guy Stevens who owned on prior to his 46 and is extremely knowledgable and works in the iddustry.
My 77 had lots of blisters and after peeling the bottom and letting here dry out, I put a new epoxy barrier coat and bottom on. All the blisters (~1500) were dime shaped and superficial with the exception of 2 that did penetrate the matte a little. The 2 in question were still not structural and were easily detected and different from the remaining ~1498. I also put a new rudder on since I was not sure if the old one was saturated since it had a small stress fracture. I used the old stock and in the process, confirmed that the old rudder was fine.
The decks around the hand rails tend to have water ingress that can be an issue, but rarely to the boat of it compromising the boat. It is, however, something that needs to be address and is tyipcally handled buy addting a handrail inside that links to the exterior handrails. Check the documents section for a summary on how to do that.
In short, I have heard very favorable things about the 39. Martin King is on the list and owned on so you might hear back from him. He is a great resource as his father designed the boat and he lived near the Ericson facility if memory serves me right. Also, Seth was the warranty manager for Ericson and you will likely hear from his as well for any 39 specific pros/cons.
In the interim, take a look at the following posting from Guy and stay tuned. You will find this list to be of incredible value.
Cheers
Shaun
Check out the link below from Guy Stevens
http://www.ericsonyachts.org/infoexchange/showthread.php?t=2334&highlight=39