It's only 35 years old and it's Grade 3, it may be OK - just a bit slower and slightly less contrast.

On the other hand this was developer incorporated and just immersing it in an alkali solution was enough to develop it, I used tp process it in a home made activator in an Ilfoprint machine I used Hypam 1+4 instead of stabiliser and then put it in a weaker 2n fixing bath before washing & drying.

Ian