For anyone interested: The added rear sling swivels on the reworked K98k rifles are the same as what were used on wartime Hungarian 43M rifles. That makes perfect sense, but also suggests either spare parts quantities exploited for these, or otherwise unusable 43M rifles being cannibalized to cobble together whole, functional rifles in the post-war period.
There has been a rumor that 43M rifles continued to be assembled in small basement workshops during the Siege of Budapest, but never anything like recorded accounts from survivors, at least outside of Hungarian speaking audiences. Bear in mind that the factory for both the 43M and G.98/40 rifles was on Csepel Island on the Pest side of the river, and was subject to Soviet occupation as early as late December 1944.