Old 1962 cast iron flange (?)

I am replacing our vinyl flooring and noticed my toilet flange doesn't look like any I've seen yet. It is solid cast iron with no "slots" for the flange bolts, just two old rusted bolts sticking up. It appears to me sweated on with lead. The pipe itself is jagged (where it was cut with a torch?) and sticks up above the flange slightly in spots. I have no real problems, no leaks or buckled floor. It (flange) does sit level with the floor, not slightly above. the wax ring with horn works fine. I guess my question is, if I accidentelly break one of the bolts how do I replace it? is it the screw in type or the kind that has the flat "head" under the flange?

Having the jagged pipe sticking up is it possible to add an extension?

Are you on a basement, crawlspace or slab?

crawlspace below

flange

remove the "rusted bolts" and you will have the necessary slots for the new bolts.

I'm assuming then that the bolts are screw in type? there is 2x6 t&g subfloor under...

You have a lead and oakum jointed closet flange on cast iron pipe - I still do it today - though it can be a pain.... rusted bolts should just be studs screwed through the sub-floor... (wood thread on one end and machine thread on other...)

I still have a picture of 5/16" closet bolts, with flat bottoms that slide into elongated slots on each side of the flange. Scrape the top of the flange real good and see if you can determine if those are closet bolts or closet screws.

The jagged pipe was probably cut off with a hammer and a 3/4" cold chisel.

What extension are you talking about?

You always have the option of going under the house with a set of snap cutters and cutting the cast iron pipe and replacing it with PVC pipe and flange.