Guys that do heavy commercial truck tire replacements on the side of the road are the best ones to search out for split rim assembly as they are used to bustin' down tires & rims & installing new rubber on the side of the road with nothing but sledge hammers & pry bars.
My tire guy had no problems with mounting tires, tubes & flaps on the original 3 piece 8.25 X 20 rims for my '54 COE.
Been driving on them for years now with no problems.
But...I did take him nice painted & powder coated parts to assemble....
