Greetings, with the help of this forum I was able to confirm proper ISP programming of an ATMEGA328P IC with the Willem (Sivava make) PCB4.5 unit and the latest software.
Here is the adapter schematic (pinout, actually) adapting from the 25CXX SPI port to a standard 6-pin ISP header.
Photo programming the Arduino Duemilanove via ISP using Sivava's 98D12c3 software:
Thank you for your help!