Derek, the last burial register at the Belize National Archives, which I've transcribed and will be in the third book of early Belize records, ends at 1841 - no Frickers or Lyons, sorry.The Usher family continued in Belize.There are no accessible records after 1841, unless they are at St. John's, which seems unlikely as when we first visited in 1982 a clerk at the church told usthat all their early records had been sent to the Archvies.
I've photographed all the MI's at Yarborough Cemetery for the book - again, no Frickers or Lyons. There is a plaque to John and Sarah Purcell Usher in the church - both were born and lived out their lives in Belize.
Your families may have gone to Australia, South Africa, or the U.S. If they disappear from English records, I'd guess Australia as the most likely destination.If they were in the logwood cutting business, Burma was opening as a source of teakwood - a Potts born in Belize married an Antram who changed from shipping mahogany and logwood in Belize to shipping teak in Burma when the mahogany/logwood trade in Belize collapsed after 1839, when it became difficult to get workers to cut the wood. And when Marshal Bennett died in 1839, William Cooke who had worked in his business left Belize for Adelaide.