My first advice in dealing with Heller kits is to do with the decals, as their decals have always been a hit and miss matter in my experience.
Give the decal sheet a shot of clear coat. I've occaisionally had trouble with heller decals having rough edges because the colored portion extended a bit beyond the carrier film area (I had to find aftermarket French roundels for a 1/72 Mirage IV due to that problem).
Also have plenty of decal setting solution on hand, I've had trouble in the past with Heller decals being slightly rigid and brittle and prone to breaking up, Also, the adhesive on them can be a bit questionable. I had a SAAB 29 from them that had wonderful decals then a Ferrari from them that I couldn't get the decals to stick with anything.
You may also find some Heller kits have a slightly pebbled surface texture on their parts that, depending on your planned finish, may need a light sanding to get rid of.