Hi.I am not related to your family but did a little internet searching.You may have already found some of this information?
It looks like your Jack, Jacqueline, Karen and Ruby were born of Probasco Father and "Pearce" mother.However, someone else named Sharon Tate has posted (at www.ancestry.com a genfile) that shows his wife's maiden name as Stuby (perhaps a later wife, but not the mother of his children?)
The birth of Jack Leslie Probasco (Lesley/Leslie link) was 02 Sept 1955, mmn Pearce, b. Orange County, CA.
At www.anybirthday.com (tries to suck you into doing their paid search) it lists the same man, same birth date with links to zipcodes 92627 (Costa Mesa) and 92325 (Lake Arrowhead).These are probably older addresses for him.I would think Arrowhead might have been a vacation home or something?Very few people live up there.There is also a Grover Probasco living in Highland, CA (just below the mountain where Arrowhead is)Since you have Jack Leslie's name and birthdate, there is another way to find him (at a low cost).Go to the Cal DMV site, I can't remember the exact www address.There is a place in there where you can pay $5.00, give a full name and birthdate, and they will send on your letter or info to the last address the CA DMV has for the person!Then the person decides whether they want to talk to you.Pretty neat, huh?
Also, I would guess that Jack Leslie Probasco's children, if born in OC, Maybe? ARE:
Probasco, Mark Leslie, b. 14 Jan 1986, mmn Lyons Probasco, Mary Elizabeth b. 02 Dec 1988, mmn Lyons Probasco, Ryan Elliott, b. 23 Sept 1984, mmn Lyons
There is a death record for Ruby R. Probasco at the Cal Death Index site, site at www.rootsweb.com.Perhaps Jack Probasco's mother, Ruby.Interestingly, I think she reportedly died in Placer County or somewhere close by there.Perhaps other relatives up there...Ahhhh maybe that explains your email address re CCSD....I guess you are in Contra Costa County?
Anyway...if the DMV trick doesn't work in finding Jack Leslie Probasco, I would think it would be worthwhile to use KNOWX.com or another for $40.00 or so for a recent search, since you have his birthdate, I think?
Also, there is a Marguerite Probasco listed as living in Costa Mesa, zip code 92626 (next to 92627, Jack's old zip code).She is listed at www.anywho.com on the internet phone directories with two addresses in Costa Mesa and one phone number.