... in light of my current research.
Mothership held my order for isolator mounts to inform me they are changing vendors from Vibration Isolation Products (now owned by Desser) to Barry. Price will change from $125/mount to $140. They have three pcs of old stock remaining and don't recommend mixing them - what would I like to do?
Got online and learned that the VIP # for the equivalent of the Lord 3804-20 is a VIP 50804-20. I found those for sale at Spruce:
08-07108 VIP ENGINE MOUNT 50804-20 $114.75
Assuming these are in fact a suitable substitute, I will be ordering and installing them - and reporting back here. I still plan to get the bolt kit from Van's - eliminates uncertainty and seems to be competitively priced.
I wanted to help out any other -10 builders looking for isolation mounts.
On a semi-related note regarding pricing, I'm told by B&C that the four genuine Lycoming studs they sell as part of their alternator/oil filter adapter spacer kit cost them $80 each.
If so, they're not making much on the $360 kit price. Makes one wonder if someone besides Lycoming makes an airworthy stud for this application.
Aaaaaaand... they're showing no stock at East or West. I guess we'll see how long this takes. Can't afford too much delay here as I'm almost out of things to do besides cowl and baffle/FWF.