Asking for a friend with an R50....Transmission shifts fine, but the lever is very stiff moving side-to-side in neutral (like the end is "anchored in Silly Putty"). Any ideas what the most likely diagnosis is? Bad shift cable? Bad lever assembly?

 

Cables would have made sense when shifting through gears not gear lever play when in neutral. Pop the gear boot and have a look beneath, there should be a large plastic ring holding the lever in. Try to lube that and give it a go. This is the easy solution