I'd bet they don't fit. Checking with A1-Electronics that sells OEM-style kits they list 68-72 Elky, 68-70 sedan (post) and 70-72, nothing for 68-69 hardtop/convertible. The fact the 68-69 hardtop aren't included with the 70-72 tells me the 69 won't work the 70 window mechanism.
Have you looked into "universal" kits like those from autoloc.com. I have 4 of these in my 67 and they fit over the factory window crank leaving the original x-mechanism in place in case you ever want to revert back to manual windows. No doors to take off off try to hold the glass up while replacing the x-mechanism and fitting a motor...a fairly simple installation.
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