I know of a Ebay seller I bought some NOS/NIB radios from that's sitting on five NIB/NOS HR2510's with the Chipswitches installed that he bought new if he still has them but he can't sell to you on Ebay. You have to do a private sale.
Oh yeah,he's wanting $500 a pop.
Man that's tempting, but the price is not worth it imo. I have owned the HR 2510 and Lincoln and both mine had the Chipswitch in them. Sold them along time ago. Its just one of those models that will make you pay that price for another chance at one.