For the sound, I have this for my 1970NXP:
https://www.amazon.com/NEC-Soundbar-Attachment-LCD1970NX-BK-LCD2070NX-BK/dp/B00078V9VE/ref=as_li_ss_tl?ie=UTF8&linkCode=ll1&tag=atariage&linkId=42df9021459ea757d2fa48612535fef4
May it be compatible with your 1970VX?