Capri Brakes - missing retaining pin

For many months, my white XL has had a squeaking noise coming from the front right wheel. It had something to do with the brakes and I finally decided to have a look. It didn't take long to see that the lower brake pad retaining pin was missing! (see photo) I have no idea how long it has been like that as I have driven it to a number of places.
I had an old front calliper in my limited spare parts bin and it had the two retaining pins so I was in luck. Well, for a few minutes! I cleaned it up & went to put in in the slot but it was way too thick. Must go the other way - no, not that way either! I don't believe it! I withdrew the existing pin & it was very obvious that the pins were completely different in diameter. Where can I get the proper size pin from?
My local Repco store couldn't help so I drove to All Brake & Clutch at Rocklea who are always helpful. The guy laughed & said no hope but told me what they do is insert either a big split pin or a long thin bolt. Good advice, so off to Bunnings where I bought a packet of 3/16" x 75mm bolts & nuts. See the differences in the photo.(The one in the middle was the one I was trying to replace.)
Luckily, these bolts are a good fit & will have do until I can get an original type of pin. Hope this stops the rattle as it was too late to test drive it today.
Again, it seems that every Capri is different & I am not sure what types of callipers were used but the white one has a Girling set.