This is a much better answer than the one I gave, but I still find my solution to be more amusing in light of your concern about scraping the bottoms of your leather soles. They are leather soles and will look like crap where the gum is after a few months of wear. Scrape away.
I've done this successfully, but I recall my tailor telling me it depends on the fabric. I believe a lighter colored worsted fabric is more likely to show where the stitches were as compared with darker colors or fabric with some texture.
It's more than that. I took in a pair of tropical wool pants yesterday to get the legs slimmed to match my flannel pants (both American cut). My tailor said there was a 2 inch difference in the thigh and 1.5 inch difference in the knees and leg opening. That's more than fabric.