Replacing the oleo's on my mains. 415-C

Ercoupe Service Memo #68 addresses the hydraulic fluid compatibility issue. In a nutshell, Serial Numbers 1 thru 812 have a rubber cup in the strut that is not compatible with 5606 hydraulic fluid so they recommend DOT 3 hydraulic fluid when filling the strut. If you have the later O-ring instead of the cup, the O-rings are compatible with 5606 hydraulic fluid.
www.univair.com/content/ERC_SM68.pdf

You can find a discussion of the spacers here, I think these are the ones to which you are referring:
www.ercoupeparts.com/spacers.pdf

I'm reading all that I can on ercoupe.info about replacing the oleo's on my 415-C. It's pretty well detailed except for the part where it says to check the hole in the bottom of the piston. It says "Note that the cap is serviced with brake fluid & the O-ring with mineral hydraulic oil". My question is: Are they talking about filling the piston or just cleaning the rubber/O-ring? At the same time....it says in the service manual (or somewhere I read) that you should add a 7/16" spacer under the oleo. The fellow at Univair said he's heard of this and it's a good idea but don't have any. Any suggestions or comments?

Thanks in advance,
Cal N99155