Blue door panel
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=280189879379&sspagename=STRK%3AMEWAX%3AIT&viewitem=
inner fender LH
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=320212355114&sspagename=STRK%3AMEWAX%3AIT&viewitem=
inner wheelwell rear
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=250239514087&sspagename=STRK%3AMEWAX%3AIT&viewitem=
grill cougar 87
http://cgi.ebay.com/ebaymotors/NOS-1987-1988-Ford-Mercury-Cougar-Grille-Black-87-88_W0QQcmdZViewItemQQ_trkparmsZ72Q3a570Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem110333021051QQitemZ110333021051QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
found some more
83-84 glove box door
http://cgi.ebay.com/ebaymotors/1983-UP-FORD-THUNDERBIRD-GLOVE-BOX-DOOR-NOS_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ46093QQihZ015QQitemZ250219589461QQtcZphoto
box fox lockset
http://cgi.ebay.com/ebaymotors/1980-1982-NOS-Ford-Thunderbird-Lockset_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ6763QQihZ011QQitemZ320122105627QQtcZphoto
84 park lamp L
http://cgi.ebay.com/ebaymotors/1984-Ford-Thunderbird-LH-Parking-Lamp-Assembly-NOS_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ10076QQihZ015QQitemZ250223304216QQtcZphoto
84 park lamp R
http://cgi.ebay.com/ebaymotors/1984-Ford-Thunderbird-RH-Parking-Lamp-Assembly-NOS_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ10076QQihZ015QQitemZ250223305550QQtcZphoto
83-84 rocker molding
http://cgi.ebay.com/ebaymotors/1984-1985-Ford-Thunderbird-RH-Rocker-Moulding-NOS_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ10076QQihZ024QQitemZ370107677656QQtcZphoto
box fox grill
http://cgi.ebay.com/ebaymotors/1980-1982-FORD-THUNDERBIRD-GRILLE-NOS_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ10076QQihZ024QQitemZ370095037275QQtcZphoto
84 gas tank
http://cgi.ebay.com/ebaymotors/1984-Ford-Thunderbird-Gas-Tank-NOS-E4SZ-9002-B_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ10076QQihZ011QQitemZ320128549671QQtcZphoto
IMO some of it is pricy, as always supply and demand, if you need it try submitting an offer