OK. the man's suit is an 1870's style but being older he may not be up to date.
There isn't much to see on the lady but what little there is also indicates an 1870's date but could easily be into the1880's but her hairstyle looks a late 1870's fashion.I think there's more to this pitcure than what you see here,the arms are cut off as is the lower body.late 1870's - early 1880's I would suggest.
jim