SWB seat specialists, give us all you got

[pss]

I have a handful of seats of which I do not know what year they are and hence, which replacement parts to order to restore them.

For example Sierra Madre, regarding the plastic recliner mechanism cover sets they offer 2 sets and distinguish between 66/67 and 68.
e.g.
901.521.915.00 for 1966/1967 (in grey-ish plastic) driver seat
901.521.915.10 for 1968 (black plastic) driver seat

For 65 911 they do not offer anything.

Few questions:
How can one distinguish between 65, 66, 67 and 68 seats?
Would 65 seat mechanisms and parts be the same as 356 for which SM offer 644.521.915.00 for 64-65 (grey-ish plastic) driver side?
Who produces/sells the best seat mechanism replacement parts (washers, caps, knobs, springs, nuts, screws)?
The below pics are all parts from 2 seats, What year would they be, or maybe 2 different years?

[Jim Breazeale]

How can one distinguish between 65, 66, 67 and 68 seats?

Yes, and no. There will often be a ink stamp with a date on it on the inside of the mechanism.
65, 66 and 67 seats are virtually identical and have tan plastic covers.
They all lock on the RH seat (we are talking about LHD cars) and don't lock on the driver's side.
68 seats lock on both seats and have black plastic covers. OK, I know that ROW cars can have tan covers.
68 seats came with built in headrests after Jan of 68

Would 65 seat mechanisms and parts be the same as 356 for which SM offer 644.521.915.00 for 64-65 (grey-ish plastic) driver side?

Again, yes and no. They look identical to a 65 356C but have one small difference inside the mechanism. Yes, they both have grey or tan (grey-ish?) plastic covers
Who produces/sells the best seat mechanism replacement parts (washers, caps, knobs, springs, nuts, screws)?

I don't know of anyone that does that.
The below pics are all parts from 2 seats, What year would they be, or maybe 2 different years?

Where are the rest of the parts?
You have parts for 2 65 to 67 seats. The 2 parts on the right hand side of your picture for for a left hand seat. The 2 pieces or the left hand side are for a right hand seat

[pss]

Jim txs! I found the dates, 1965.
Now the question is what to order for repair parts. All is ok to restore, except for the plastic washers and the tan plastic caps.
Anybody any advice where to look best for these?

[Haasman]

Sierre Madre Collection sells the plastic caps. (Repos)

[pss]

Indeed found them there and got them meanwhile. Beware that for the early 911 you need the caps listed under 356 at SM.

[Adore911]

Parts-wise in The Netherlands has them too.