Seen pics of them... 'Living in the Past' would likely know. I can't imagine them being all that hard to rebuild... I'd go for it. Make gaskets with a ballpeen hammer and shell casings, and repack them with fresh grease.
Those were the first hubs I ever put on my ’68. Very simple inside, it has a ‘star’ shape that goes on the axle and the two levers that rotate a slotted pin. If you rebuild them, check for cracks on the ‘star’, that’s where mine broke.
They (Dualmatics) were a dealer installed option on my 72. They still work like a charm after 42 years. They get a lot of attention since few folks have ever seen anything like them. The simplicity is hard to beat.