Lee...
Afterthoughts....not all that useful, maybe.
1) My memory re Selley was only 'Half-Off'....HO! Walthers sells your reel mower and a lawn roller by Selley in HO...
Mower Link
....which, of course, frustrates further those of us in O scale to think that something like a reel-type mower is available in HO from a company, but not in O......from the same company!!! (Maybe you could soak the HO version in a solution made from a blue pill to make it....bigger?)
2) We might gently prevail upon Dennis at Arttista to consider this sort of mower as a detail item for his line. After a couple years of prodding, he did, indeed, come through for me in releasing a figure looking through a set of binoculars....the perfect addition to my forest fire tower platform. THANK YOU, Dennis!!! Now....a reel type mower.....maybe??
3) I also believe that one of the British figurine manufacturers has done a reel-type mower. I'm sure I've seen one in O scale, but it was years ago. This sort of mower is/was just the thing for an urban gentile gardener in the UK.
4) A derelict Harrison's hardware is one of those things to keep an eye out for at flea markets, trains shows...even York meets.
5) BTW...you are aware, arent' you, that the O scale Harrison's Hardware is offered in kit form, item PF5891,...
Hardware Kit Link
...and if you look at the exploded view in the link above...lower center....whaddya see?...the mowers!! Of course, it'll cost you to get them.....unless you're inclined to build the rest of the kit and dispose of it (sell it) to recover some/all of the cost. Hey......just a thought!
6) Andre Garcia, River Leaf Models, has been responsive to request for these sorts of details. Andre?.....whaddya think?
'nuf for now....
KD