GTV6 door retainer - advice requested

[AlfaACT]

I recently had the misfortune of the driver's door opening too wide and some consequential damage to the leading edge of the door - ouch!
It resulted from the coincidence of a number of conditions.
1. doorlock did not "catch" when the door was shut;
2. gravity assisted its reopening;
3. the retainer did not do its job!

After dismantling the retainer I notice that I have two versions.
The one on my car (an early '84 model) is basically a bent steel bar with hole for the clevis pin at one end and a couple of "bumps" near the other end. It seems that the "bumps" are intended first to check the door movement and then the second to prevent it from opening too far. However wear tends to render the mechanism ineffective.
The "spare" retainer that I have, also has a dowel pin through the bar just after the second "bump".
See pic attached.

Queston 1:
Is the version with the dowel an upgraded or later Alfa modification or is it just someone's (ie previous owner or service agent) clever fix?

Question 2:
If I use the "spare" retainer (ie with the pin), and if the door swings wide again, will it risk damaging the inside of the door or the door frame?

Peter.
PS. The door lock has been fixed!