Difficult to see in pic but wanted to demonstrate the PZ on each side were the same. It is due to the internal mechanism of the door that lends itself to needing the two shorter spindles.
Your existing handles are lever/pad so technically you should already have a split spindle in there unless someone before you has swapped it for a solid 1 piece type, usually because the split follower has failed in the mechanism
Is there a problem with the handles or are you just looking to spruce them up? Im just thinking you may have better luck trying to repair or repaint them than find new ones.
There must be someone making replacement handles though.
I have an identical door with the same handles (minus the thumb press), but unfortunately, the gearbox is damaged. It requires some effort to lock or unlock the door, and upon inspection, I noticed small debris from broken pieces after removing the front plate. I've tried searching online and found the closest match to be the "Union Monarch L22180" gearbox based on visual inspection. However, I'm uncertain about how to remove the gearbox. I can remove the handles, front plate of the gearbox, and euro cylinder, but I'm unsure if this will provide access to the gearbox, considering there are likely internal connections for shooting bolts. Any guidance would be greatly appreciated.
P.S.: Do I need to buy this expensive "Union Monarch L22180" gearbox, or are there more affordable alternatives available?
Union Monarch L22180. - Eventually I managed to fix my gearbox after removing it. It was easy to remove the gearbox ( or disconnect the bars for multilock ) , they are only connected by hooks.
Union 2828 Monarch Lock Replacement Guide
The Union 2828 Monarch lock features an L22180 central gearbox connected to hook, shoot bolt, or deadbolt cases at the top and bottom. These are linked by rods, which are secured to the lock case by plastic sliders.
Remove Faceplates and Handles: Start by taking off the faceplates and handles. Be cautious during this step to avoid scratching or damaging the handles. Older handles may have brittle plastic clips, so handle them with care to prevent breakage.
Access the Rods: Once the handles are removed, look through the slots at the top and bottom. You will see the rods attached to a bracket by plastic sliders clipped over their ends.
Unscrew Gearboxes: Unscrew all the gearboxes to allow some movement. Pulling out the case will reveal the plastic sliders.
Unclip the Rods: Carefully slide the clips away just enough to unclip the rods. Note that some models may have a bolt securing the clip, which must be removed first. Avoid dropping the plastic clips into the door cavity, as retrieving them would require door removal.
Replace Gearbox: After changing the gearbox, push the rods back onto the gearbox and slide the clips back down to reattach the rods. Again, handle the plastic clips with care to avoid breaking or dropping them.
With patience and a delicate touch, the replacement process should go smoothly.
The first picture shows the rod from the side along with the white plastic clip. The rod has a space or hook that connects to the bar in the lock (as shown in the second picture). The white plastic clip slides down over this connection to secure the rod in place.