As a matter of fact I changed out my DISA valve on my 2003 325iT in April timeframe - bought the new one from the dealer in San Diego, and my original factory one is in my garage. I wasn't sure what to do with it, it seems to be fine under close inspection, the seal looks good and the actuator isn't flapping around.
Make me an offer and I will sell it to you - otherwise I will put it up on Kijiji this week. Can meet in Durham Region, or GTA if pre-arranged after work.
PM me asap.