Just ran across the cartridge belts in the link below on eBay. They're a steal at $19.99 each BIN + $9.99 for shipping. They look to be Greek issue, so no worries about actually using them. The only negative about these belts is that there are no rivets to attach M1945 suspenders. M1910 web gear hooks / hangers still attach to the lower rivets though.
http://www.ebay.com/itm/321024426309?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.ebay.com/itm/321024426309?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649