Based upon the advice in this thread (Thanks!!), I contacted DAN for a doctor's referral. They sent me a list of pulmonologists (none closer than the Bay Area) and another of doctors who have registered with DAN and are closer to Monterey.
There was also a long spiel on diving with lung damage that echoed what DDM said: get approval from a pulmonologist (preferred) or a doctor with a dive medicine background before resuming diving. Since there was some interest in anything I learned about the topic, I'm including their response here:
"Thank you for contacting Medical Services of Divers Alert Network. You have asked a very reasonable question regarding pulmonary injury and scuba diving. Since barotrauma can occur with hyperinflation of lung tissue, a diver’s lungs must be able to tolerate rapid changes in volume and pressure. Fibrotic or scarred tissue may be of particular concern to the SCUBA diver since it offers a reduced compliance through its interfacing normal lung tissue. Any weakness in lung structure or architecture may be predisposed to rupture from even slight over-inflation. Pulmonary barotrauma usually happens towards the end of a dive, including from a shallow dive, and refers to rupture of the lung air sacs (alveoli). Gas that escapes can enter one of three places:
(1) the area around the heart (causing pneumomediastinum or mediastinal emphysema);
(2) the pleural space between the lung and chest wall (causing pneumothorax);
(3) the bloodstream (causing arterial gas embolism, AGE).
Following a trauma induced pneumothorax, there is lung injury. That lung injury may have healed uneventfully, no scarring, no fibrosis, no further risks. Or it may have healed with scar tissue, adhesions, or a weak section of the lung tissue. While a history of a pneumothorax may not be a problem above water, a pneumothorax occurring underwater with the expanding pleural air on ascent will cause a lung collapse. This event, known as a tension pneumothorax, may not be survivable for the SCUBA diver. Some individuals will be able to get medical clearance to dive following a traumatic pneumothorax, some will not.
Please see two following emails. One will be for dive medicine experienced pulmonologists, and is the preferred route for an evaluation. Unfortunately, the closest in the DAN referral database is in Palo Alto. The second email is for other physicians with a dive medicine background. They may or may not be able to assist, I am including them because of location.
Once evaluated, and assuming your wife is medically cleared to dive, it is also a good idea to have the medical clearance in writing. When you complete the requisite medical form for any dive location, the past history of a pulmonary event will likely trigger a red flag for the dive shop or resort. Having a letter may smooth the process. It is also a good idea to discuss your medical history with the dive destination prior to your arrival, to ensure they will accept the letter, or any other documentation they may require."
