Unthreaded #10 spacers should fit M5 in most cases. Inventables sell 1/4" nylon spacers, and I have both 1/4" and 3/4" in my store
. The spacers are extremely light, so I can post them worldwide. Use the 'contact me' link at the bottom, tell me how many you need, and I'll give you the postage cost. I will also have 1" spacers in a few days.