Identifying Gibson ES 175D

[TTerBorg]

I have a Gibson ES 175D I am prepping for sale. It is in pretty good condition and I believe it is an early 70s model. The serial number is etched on the headstock is a bit difficult to read but is either 135406 or 136406. (See attached). I was hoping someone might help me nail this down.
In addition the guitar is in really excellent condition. Exceptions are that it was used a lot so some belt scratches in the clear coat and some minor scratches here and there as to be expected. A;; parts are original except the pickguard is missing. Any thoughts on optimizing value before selling are welcome. Should I go ahead and find an original pickguard ($400 to $500) or will that not increase value commensurately? Should I go ahead and get the scratches buffed and cleaned off? And advice is welcome.

[jdgm]

Well those machine  heads are not original!  You still have the screw holes and marks from the original Kluson-type machines there.

I don't think an 'original' pickguard is worth getting, or that it would increase the value by that much.   A custom-made repro guard is just as good.

https://www.ebay.com/b/Es-175-Pickguard/41424/bn_7023284407

http://www.thepickguardshop.com/Gibson+ES-175D+®+Pickguard+PVFqTnpBRE14b0RkalZIWnZKSGM

Obviously the better and cleaner the guitar looks, the more it will be worth.

Good luck.

[TTerBorg]

Thanks for the info!