Zero, or close to it. Actions like that have values only when there is a matching piano.
Notice the three spaces in between the four groups of hammers? Notice some hammers being at an angle compared to the shanks? These are the biggies, but there are many other details. Only one manufacturer is able to take an action from a piano, put it in another one and have it work with limited amount of work. That manufacturer is Yamaha and even that only for some models. Actions are quite customs, and since somebody gave this to you its corresponding piano is gone. Chances to find a similar one are zero. Putting this thing inside something else will require an amount of work very close, if not more than building something like that from scratch. As such, it has no value for that purpose.
On the other hand, to build an hybrid, it's almost perfect. Why do I say almost? Because it's missing the cabinet and if it had one, even a damaged one, it would be much easier. Why do I know? The cabinet I had was very damaged, so I embarked both in restoring and building from scratch to see what was easier (since I had limited woodworking capabilities). The former won hands down: building from scratch was too much work for me. Depending on your woodworking skills and equipment you might think differently.
Khuja Wangtishvili unfortunately it looks like from baby or a small grand, but maybe it's even better?
It's great. Actually long grands have actions with too long keysticks. Whatever digital piano people say about pivot point (longer is better, they say), that is not true. After a certain point too long is worse. Yours look like is around the sweet point.