That looks like the dense pump I have on my 250 hp 6 bta with the a in the intake marine engine. I have quite few marine engines, both b and c and I have never seen a Nippon denso above 300 hp. I have two of these as spares on a shelf, but have mainly been going back with bosch's. I think I paid about 1200 new each many years ago for the ones I have. If you find some one with that marine engine or a 210 b with a rotary( works as a swap), it should be desirable for them if in good shape.
For the marine application at 250hp I never had issues with pump, they worked well and long, which unfortunately left me with two spares sitting, and that is not what I expected based on comments from others relative to quality.