www.EarlyLDS.com (actually lists anyone who lived in Hancock County from 1839 - 1855-ish) lists Adam Pilkington as having one of the few remaining headstones in the old "Mormon" cemetery on the east end of Parley St. His headstone (Blk 11, lot 5, grave 14) is supposed to read:
ADAM Pilkington
DIED
Feb. 11th 1856
Aged 46 yrs.
2 mos 8 days
Property owned in Nauvoo:
KIimball1st: Block 4, Lot 52
Kimball 1st: Blodk 4, Lot 54 (both of these somewhere around Warsaw and Fullmer streets, along White)
Property owned in Hancock County:
T6 R8, Sec 8, NE, 21 acres
T6 R8, Sec 8, Sub SW, 9.55 acres (this would put the farm along County Road 900 N, between 2300 and 2250 E in Sonora Twp, right outside the city limits of Nauvoo, near the old Mormon cemetery.)
I would suggest checking with the courthouse in Carthage before purchasing any of these!

Jane is listed as being buried in grave 12, which, I believe, all the evens are on one side, odds on another, so she is next to Adam. Tombstone is supposed to read "Died at age 68 years 10 months 6 days"

Nothing shows up for the Webbers, sorry.