Unfortunately, while there appears to be some kind of COA with your items... these artifacts are nearly impossible to specifically confirm as previously exhibited at Disneyland. The COA appears to lack the necessary information that would be relied upon in demonstrating clear provenance.
Except for the Disneyland golden horseshoe that was sold at Frontierland souvenir shops... the rest of the items were unlikely to have been created by Disney. While it's not impossible that that they were once exhibited at the Big Thunder Railroad attraction at Disneyland (not as originals; but as generally available western themed decorations)... without specific photographic evidence and the names of those who maintained custody of the items since their removal from the park... they're not of particular value as Disneyland collectibles.
Perhaps the prior owners can come forward and provide the background you would need... However, at this point, while they're interesting as decorator pieces, they're not useful for much else.
