Based on the usual formula, your 25 time suggests you'll do a 2:01, but realistically your 59 on the H25/1 is probably a better guide, in which case 2:03 or 2:04 seems more realistic. If you get under 2:05 you can consider it a success as a début.
That 59 was a horror show though, I did half of it on the base bars thinking about quitting, because it was too hot and I needed a drink.
I'll go with 2:05 as a guide to try and beat. My disc punctured this morning so me finishing is dependent on the Zefal puncture spray stuff holding up.
Based on the usual formula, your 25 time suggests you'll do a 2:01, but realistically your 59 on the H25/1 is probably a better guide, in which case 2:03 or 2:04 seems more realistic. If you get under 2:05 you can consider it a success as a début.