I think I understand it, but just wanted to make sure.
I save at certain times like 1:11:11 at save points (not temporary save points) with only 10, 21, 32 or 43 item in inventory (including key items if I read correctly) and I only get one item associated with that time?
That's bang on. It's only a matter of timing. Two things I used to do; stay in the menu screen until 6-8 seconds before the timer ran out, then quickly click out and make sure Koudelka is lined up at the font. (She has a habit of moving slightly when you enter the menu). Then press X and hope for the best. I always kept two save files in case I messed up. If it's worked, when you load the game you'll get a different noise in the loading screen and your save time will be 1.11.11, 2.22.22 or whatever. You only get one special item per save but some of it is unique.
Incidentally the lazy way of doing it is just to leave her stood at the font with the appropriate number of inventory items and save when the time is right - prevents you having to screech back to a save point and re-organise your belongings in a hurry. But you may have worked that out already :)
Good luck anyway. --- --- I made a mistake in my sig, how do I get this Tippex off the screen...?