babcea, when I had to find a remote for my Toshiba TRX-1820, after searching high and low on the 'net I finally just "saved" a search on eBay (automatic email notification) for what I was looking for and one popped up within a couple weeks. You might have to buy a receiver to get the remote, most of the old analog receivers seem to go for $25-$50 (mostly just the cost of shipping), good luck.
IF you put in "uniden remote" on Ebay there's a bunch of remotes. I don't know if there is a remote that might work for it but be a different model. I know the Toshiba 1420 remote will work with a 1520