I have read here before that in the US, the side opening lid was only on Kenmores.
In Australia, all belt-drive Whirlpools had a side opening lid - the machines were made in Australia by Malleys, under license to Whirlpool corporation, and were uniquely Australian models, using many Australian components. (I have no idea what percentage of the machines were Australian made components, the other Aussie members may have better info than me.)