looks like you have really done your homework.I looked at everything I could find on the Brays in Maine.Melzar is not mentioned.One thing I did notice (maybe you did too) is that the only Bray families early in the Phillips/Avon/Strong area were Israel & Daniel.They were brothers and sons of Israel & Jemima Bray.The 1810 census has 3 males under age 10 for both Daniel and Isreal. It has two males age 10-15 for Daniel and one for Israel. It has one male 16-25 for each also.
I have access to some VR of Poland, ME (A stop on the way for these brothers who ended up in the Strong area).It says Daniel & wife Elizabeth had sons Libbeas Apr 1794, Sulevon (Sullivan) Sep 1795 and Daniel Jul 1797. (I checked the census and all of them were still living in 1850) You have probably already seen the cemetery info with Israel's sons Eliphalet b1798, Nathaniel b.1801, Jacob b.1805, Israel R. b.1808.If the numbers on the census are correct then:
Israel's male age 10-15is probably Eliphalet his three males age 0-9 are probably Nathaniel, Jacob & Israel R.
Daniel's male 16-25 is probably Libbeus his males 10-15 are probably Sullivan and Daniel his three males 0-9 are unaccounted for.
I noticed Melzar is listed as age 49 on the 1850 census.He could be one of Daniel's males age 0-9 in 1810 especially if he was born the second half of the year in 1800.Maybe you can find out how to get a copy of an early Maine will for Daniel Bray (b.1772 d.??).I assume you have already tried to get Melzar's death record.