Database using WIN1250 encoding is handled improperly

I have a legacy project that uses WIN1250 encoded postgres database. Both the Collate and the Ctype are "Hungarian_Hungary.1250".

In HeidiSQL, the Hungarian accents look weird. See the attachment. Could you fix this, please? Thanks.

Here is a simple sample to create the postgres database and a value in a table:

createdb --encoding=WIN1250 --lc-collate=C --lc-ctype=C --template=template0 heidisql_1250

create table t (c text);

insert into t values (chr(193));

If you see the content in HeidiSQL then instead of the expected Hungarian accented a (á), you will see a questionmark in a diamond shape, similarly to the formerly uploaded screenshot.

Could you fix this issue, please?