Stripping stair paint with a heatgun? (tricky to remove substance, lead paint?)

[Bodjejob]

Image of partially stripped step below.

I'm very new to DIY so apologies in advance for any silly questions.

I am using a heatgun (350c) and ffp3 cheap mask (£5). I plan on painting over once stripped. The step (for example central section back) has very tricky to strip small parts of paint, , is it worth leaving this and just sanding over? There is also material on the left and right sections of the step that is very hard to remove (using heat gun at 350c), not sure if paint or glue or anything tbh. Also worried it may be lead paint, are the "safety precautions" I've taken above sufficient?

In short, how would I remove the material on the left and right of the step safely?

 

[Burnerman]

That’s well stripped for now, the remainder of the paint has soaked in.
Bash on with your sanding and priming!
John

 

[Bodjejob]

That’s well stripped for now, the remainder of the paint has soaked in.
Bash on with your sanding and priming!
John

Cheers John. Is it safe to sand the hell out of it if it's potentially lead (again I have no clue all I know property is 1940-60s)?

 

[Burnerman]

Well - sticking my neck out - it looks like the vast majority of the paint has now gone but I'd still use a sander with dust extraction, in good ventilated conditions......timber dust isn't particularly pleasant anyway.
A belt sander rips the surface off big time, but does leave untouched areas at the ends.
John

 

[Bodjejob]

Thanks John. What about the remnants of difficult to remove paint on the left and right panels of the step? Surely sanding that would be dangerous (if it were lead)?

 

[Burnerman]

Tricky corners can be sorted with a 'detail sander' - again with dust extraction.
From what I can see there the step is ready for a primer / undercoat as it won't strip any more. If there are any gouges in the timber, they can be happily filled with car body filler - which cures in 20 minutes.
John