OK, I have finaly dug out the spare SUIT sight I have. It is British Manufacture, & has later Israeli mods for attachment. I have put a Metric BRASS screw in the retaining catch for easier viewing.
The Top of the catch has a small hole drilled through for the insertion of the screw. This drillling has continued right through the frontal mounting bar of the sight body.
The hole is tapped to accept the screw. This is then a VERY positive way of retaining the sight on the top cover mount. BUT, it is then not READILY removable as in it's orginal form. A screwdriver or the Combination tool is needed to remove the screw completely. BEFORE the sight can be removed from the top cover mount. Most shooters will have a spare 'Normal' top cover without the mount. So it would be VERY simple to remove the whole sight & top cover assembly as one. & simply slide on the blank / normal top cover.
The issie's have also drilled through TRANSVERSELY, just in front of the rear the rear mounting alignment spigot. (This is underneath) & Two small rollers have been fitted on a steel roll pin. in the middle between both rollers, a coilled tension spring is retained. the Front of this spring has the addition of a steel HOOK, which hooks over the ORIGINAL Brit SPRING, RETAINING.
These two small mod'Attachment 38269Attachment 38266Attachment 38270Attachment 38267Attachment 38271Attachment 38268s do not affect the appearance too much & the top screw COULD be left off the lever, If desired.
I have attach some pics as requested by John, for his & all you guys perusal. If interested.