I have located a dealer with a lot of (Several 1000) vintage Gabriel shocks with an …interesting a$king figure!
What part#s would be smart to look for?
John the challenge with what you have found is that the over the counter adjustable Gabriels went through at least 4-5 different changes including shape, washer size, markings and other details. If we provided a number then you would need to examine and compare to see how far off the what you found is from what the original your looking for was like. As for numbers you can make them out on many of the examples I posted below
As part of these changes the shocks were made in three (at least) different countries as I understand it. US, Mexico and Canada
Here are a number of examples (pictures) I have of the different variations and in some cases part numbers being used during those periods
Believe this is a Stryder. Notice the much smaller (than for out shocks) upper washer on this example of a front shock

Stryders
Gabriel Adjustable "E" shocks

Styders Computer Tuned next to a 66 version. Easy to see just some of the differences

And a pair of rears

Gabriel stamped large on the main body of cover
Front

Rear

Red Ryder with large Gabriel

And another version originally painted red so might be another Red Ryder with a slightly different set of markings
