door lock mechanisms.....

Since my rebuild (new doors) I am having multiple issues with the door lock mechanisms. If its not the outer push button handle not releasing the door, its the interior door release not working. If not that, I have to at least hold up the button to allow door to release.
I reckon with the patience of a saint and several weekends I could get them fixed but was wondering if anyone has considered a less antiquated solution and fitted other door mechanisms. I was trawling the car builders forums to see if anything was available. I don't mind the door card fitment as these will be fabricated around whatever mechanism is used. I was in a truck the other day- simple mechanical mechanism and they were as solid as you could imagine, simple pull up knobs etc.
Any ideas other than sort mine- until the next time?

I put series doors on mine with the simple lift up handles...sold the fender doors and made a profit. Now i can take roof off and door tops and bask in the summer sun.

Actually the series doors fit and close/open much better than the fenders ever did...