Hello. New member. Looking for some tips to sell my old beast.

[Vols914]

Hello all. Looking for some tips in how to get my old beast up to a selling point. I hate to see her go, but for the last decade she just sits, except for the monthly trip around the block. She is a 1970 2500 3/4 ton 2wd. Pretty much original with a few changes. I would like to know how to locate a antenna that fits into the back of the Motorola AM radio (CK70A). Where to get/repair the speaker that sits on top of the radio. Where in the Seattle area is the best place for a new windshield (mine is cracked). And where to get the speedometer cable.
Some details.
1970 GMC C2500 LWB
Original 350 (truck has 130692 miles on it) rebuilt about 10 years ago. I have driven maybe 1000 since rebuild.
T400 tranny (was a stick)
373 gears
Electric ignition
Edelbrock carb
Edelbrock intake
duel flowmaster
Medium olive paint
Pretty original and straight. My brother in law bought it from the original owners son.. Im trying to post some pictures of it. Thanks all.