All which goes to the point of why guys want the assembled version!
For anyone stumbling on this thread willing to, or wanting to, work at the component level, I've concluded the best way forward is to freely ask questions if something is not clear. For example, there was a contemporaneous thread where the question was posed if the 555I version could be used instead of the 555C version (answer is yes).
Likewise, I noticed the 555CP IC chip suggested in rtr12's parts list is out of stock at DigiKey right now.
But they do have the 555CPE4 available for the same price. Can this be substituted? Answer: yes. The E4 suffix has to do with "Green" (e.g., lead-free) packaging...but I'm not sure this is common knowledge to the typical OGR reader? 
Right. 38 cents for a 0.01uF cap is simply too much! The component in rtr12's BOM is 48 cents:
There are MANY suitable alternatives for less than half the cost. But I'm not sure it's common knowledge that an X7R can be substituted for an NPO in this particular application!
And the same story goes for the resistors! Is it obvious that a 3.01M 0.4W resistor can be substituted for a 3.0M 1/8W resistor?
There is just too much fine-print for someone who's just trying to get their DCS engine to startup silently and in command mode on a roundtable whisker or yard siding!
