Schindler77-- 925 is almost always sealed with a rodium coating (platinum derivitive) to help combat tarnish--this makes it hard to resize--make sure you contact the jewelry stores in your area--as this is not a common practice for the majority of stores==they usually stick to white and yellow gold
With sterling silver,you can re-size,but only up a size or down a size,but yes ,most jeweler's will not work with it because it is such a soft metal,and hard to work with,sorry Schindler...:(