Hey there,
I'm a newbie here so I apologize in advance if I tread on another's turf and will try to step lightly. Bad puns aside, it looks like you may have a Japanese made HRA216. Your post doesn't indicate if yours is an SXA so this info may be bunk. I doubt you'll find a build date on this one but if I may ask the significance?
Re the mower, unless it's completely beyond hope, sink some cash into it and you'll have this machine for life. Read on at your peril.
Back in the day I had a turf and landscape company and used this model exclusively because they're simply bada$$ machines. After going through other "commercial" grade mowers, I bought the first one in 1990 and had a "fleet" of 10 by the start of the 1993 season. I ran them until I sold the firm in 2005. They've since been "semi-retired." Best money I've ever spent.
The only equipment I refused to include in the sale of the company were these mowers. My lead guys each got one with the others going to family and a couple others who could appreciate what a great piece of machinery it is. 8 of them, soon to be 9 are still running strong. It's going to need a carb, some brazing on the lower handle and a good cleanup. I'll post pics of the refurb'd unit once it's done. The final one just couldn't stand up to getting run over by a pickup (mine).
Thanks for allowing me this trip down amnesia lane. Hopefully I've done it right and you can follow the links. One shows the MACR # break and if I read that correctly yours is a Japanese model. I'm not affiliated with this parts house whatsoever. I've simply found them to be the cheapest of any that I've sourced.
Take care and thanks again for humoring me.
Dave
Here's what I saw:
HRA216 SXA LAWN MOWER, JPN, VIN# MACR-3000001
HRA216 SXA LAWN MOWER, USA,VIN# MACR-5000001
OEM Parts
Click on "Select Model" and it should take you to the application page where I found the above.
Honda Parts