Marking the existing statement as deprecated and adding a second almost identical statement seems excessive to me. I would suggest simply correcting the characters and if the statement has an external reference with the incorrect characters, add stated as to the reference instead.

Also, I don't know how you're currently finding the things that need fixing, but I happened to have some queries open from trying to find monolingual text statements by language code that might be useful: This query lists all the sms values for monolingual text properties for the subset of predicates that have been used between 500,000 and 1 million times (for reference, this query lists all the monolingual text predicates and how many times they're used). By adjusting the range, it should be possible to check all of them except ps:P1476.

In T308792#7943355, @Nikki wrote:

Marking the existing statement as deprecated and adding a second almost identical statement seems excessive to me. I would suggest simply correcting the characters and if the statement has an external reference with the incorrect characters, add stated as to the reference instead.

I chose the excessive route so that way the next time someone imports stuff, they can't miss that they are not the correct versions. Ideally whatever is used would show up in searches since not everyone has a Skolt keyboard so they use whatever looks close enough. So totally open to suggestions :)

In T308792#7943372, @Nikki wrote:

Also, I don't know how you're currently finding the things that need fixing, but I happened to have some queries open from trying to find monolingual text statements by language code that might be useful: This query lists all the sms values for monolingual text properties for the subset of predicates that have been used between 500,000 and 1 million times (for reference, this query lists all the monolingual text predicates and how many times they're used). By adjusting the range, it should be possible to check all of them except ps:P1476.

Mainly by accident, so that query is a goldmine! Spb! (=Späʹsseb! aka Thanks!)

I have created an item for the incorrect pal. markers and the currently correct one so that these can be used as the reasons for the preferred value and the reason for deprecation (along with error in referenced source). These have also been added to the properties themselves.

EDIT: These items do not reflect the correct apostrophe, which I should probably take into account too.

Here is a query for the lakes and ponds on the Finnish side of the border.