Lovely sets! It's very unlikely you'll find a new 994V....they've been unavailable since the 70's! An AC/HL is probably the best you'll find as a replacement or try a 164V. I restored mine about 10 years ago and you can read about it here....
https://www.vintage-radio.net/forum/...ad.php?t=11743
The volume control is difficult to replace but someone on these forums was offering replacement elements. A search will probably come up with an answer