This is why I brought it up.
"(The 35Rem I have was my grandads Marlin 336RC and while PERFECT for the job I don't want to beat and bang up this heirloom so it gets only occasional, fair weather use!) "
Don't want a scope for these conditions;
"....mostly swamp/riverbottoms where most of my shooting is done under 100-150 yds."
BTW - Pround owner of a Marlin 336C in .35 Rem with iron sights, of course (that's what it's for).
Otherwise I use one of my scoped bolt guns !