Tilt! 2203 039 is the RH-side engine mount assembly for '60-'61 Valiant/Lancer with 170 engine. It's a vertical-shear design, one piece, without a separately replaceable rubber insulator block. The '62-'66 (plus '61 225) items with the replaceable rubber block are a different, 45°-shear design. There's no reason why the vertical-shear mounts won't hold up a 225 in a car like this (as has obvs been the case on your car for some time now) but it does mean the specified insulator block won't fit your car without the '61-225-A-body-only brackets, which would be very difficult to find.
So your way forward here would be to fetch a replacement '60-'61 Valiant/Lancer vertical-shear mount. These are extremely durable, robust mounts that last a long time and tend not to fail, considerably more durable than the 45°-shear type, but we're talking about 55 years' worth of service here; eventually they're gonna fail. You may well want to have a hard look at the driver-side item, too (if for no other reason than to see which type it is). The '60-'61 vertical-shear mounts are also a lot harder to come by and tend to be considerably more expensive—they were never serviced in the aftermarket; always dealer-only parts because there was no demand in the aftermarket because they tended not to break.
I may have a NOS replacement mount for you, want me to check?
