UsedPhotoPro (Roberts Camera) is another good option. They sell through their site and on eBay. Roberts Camera is the U.S. distributor for Ilford.
Sometimes. I once bought a Horseman Optical Exposure Computer from Roberts. It was advertised as in perfect order. It failed acceptance testing because, although the battery test and low range worked, the high range didn't. These things can't be repaired, parts no longer available. I returned it for a full refund including shipping, with an explanation of why I was returning it. Roberts refunded, no problem. The wretched thing (same s/n) was on offer two weeks later "in perfect working condition." Give me a break.