Well, not a lot of success. I can't find any of them in the 1861 Reach Township census, suggesting that they moved from somewhere else. There is a Chase family in neighbouring Uxbridge Township, which may be a connection, and I can check there next. I've transcribed the 1851 Uxbridge Census, and John is not part of that family at this point, although he is probably already married.
Barbara's last name is definitely MOON on Henry's marriage registration and I did find four MOON families in Reach Township:
Moon, Samuel, Farmer, b. C.W., Episcopal Methoidst, 25
Moon, Sarah, b. England, 65
Moon, Susannah, b. CW, 22
Macdermet, Sarah, b. CW, 1
Moon, William, tenant, b. England, married 1854, Ep.M., 38
Moon, Elizabeth, b. England, 28
Moon, Sarah S., b. UC., 5
Moon, Martha A., b. UC, 3
Moon, Susan, b. UC, 1
Moon, Robert, Farmer, b. England, married 1853, Ep.M., 33
Moon, Frances, b. England, 51
Moon, Edward, b. UC, 6
McDermott, Lucia, b. UC, Reach, 16
Moon, James Sr., farmer, b. England, Bible Chr., 42
Moon, Catherine, b. England, 25
Moon, Elizabeth, b. CW, 10
Moon, William N.J., b. CW, 3
Moon, James Jr., b. CW, 1
Jennings, Dennis, School Master, b. England, Bible Chr., 22
McDermott, Mary, b. CW, 9
I checked death records up to 1908, but did not find Barbara. Possibility that she lived up to and past that date, so will have to check further records next time.
Cemetery listings were also disappointing:
The Pines Presbyterian Cemetery, Lot 11, Conc. 2, Reach
==========================================
Broken stone: In memory of Jams Bennard, son of Henry & Sarah Jane CHACE died July 27, 1883, aged 4 years, 7 months, 27 days
Pine Grove Cemetery (Prince Albert), Reach Township
=======================================
James MOON 1819-1896; Catherine Mark, his wife, 1830-1916; also 9 infant children
Next plot:
Nicholas Mark, native of Cornwall, England, died June 29, 1882, aged 78 years, 5 days
Anne, beloved wife of Nicholas Mark, died November 27, 1873, aged 67 years, 9 months, 21 days
I did find one marriage in the Ontario County Marriage Register (index entry only):
Wm. CHASE of Reach, son of John, married Eliza SHEARER, of Mariposa, daughter of Thomas, 1868
Also these:
Marriages by John Brown TAPP, Minister of Bible Christian Church in Canada at Mariposa in 1848-49
===========================================
Joseph GOULD, Mary MOON, by banns, Witnesses: James MOON, farmer, Catherine MARK, April 25, 1848, in Reach
Thomas HAYWARD, Martha MOON, by license, Witnesses: James MOON Sn., James MOON Jr., Farmer, Aug. 12, 1848 in Reach
James MOON, 30, Yeoman, of Reach, Catherine MARK, 20, by banns, Witnesses: Robert KOON?, Nicholas HARK, Yeoman, Jan. 18, 1849, in Reach
From the History of Reach Township:
Thus provided from some sources and imperilled from others, he was by and by privileged with new neighbors: and we mention them here, though they came in at successive periods, to inhabit the earlier settlements on the road northward. Eighteen months after Solomon Orser, his neighbor Mr. Mark became a settler. Next in order was Jeremish Orser, then James Moon, to the south of the Nonquon, next to Charles Black on the 14th concession, and lastly Thomas Shaw on the 11th with others at later dates.