Paul, there were two designs of the foremost fender reinforcing brackets. The early type is depicted by Tamiya in their ISU-152 kit and is a one-piece bracket that extends up the vertical inside section of the front fender and across the horizontal section. The later type...still trying to figure out exactly when it was introduced...had a separate bracket welded to the glacis, to which the upper horizontal bracket was bolted.
Both types were welded to the upper surface of the horizontal section of the fender.
On the brackets further aft, an angled steel flange was welded to the upper surface of the fender. The vertical section of the flange was drilled, as was the bracket welded to the hull side, to accept bolts that passed through the flange and the bracket and were secured with huts, usually on the aft side.
Hope this helps...
Neil