Insulation, Radiant and Vapor Barriers - Insulating crawl space under enclosed porch

We have a 1920s bungalow with an enclosed front porch. Actually from what I've learned from some of the neighbors who knew the original owner, it was never actually a porch because it served as his barber shop. Anyhow, we would like to use the room comfortably year round but it is quite chilly. The outside walls have windows all around. I would like to add insulation to the crawl spaces underneath to hopefully make it a bit warmer. The insulation there now is starting to come down. Do I need to take the old insulation out before adding new or can I apply over the old? If I apply over the old, would I apply the paper side up so that I can still see the fiberglass? We use the crawl spaces to store lawn/garden equip and would still like to do so which is why I haven't really considered blown in insulation. I would like the rigid foam insulation but the r-value isn't as high as I would like.

Suggestions? Thanks for your help. These forums are fantastic. So many questions, so little knowledge.

If I have it right it is all open down there all the time. Then Id take it all down. Start with new like a R 19 paper to the room or up to the floor. Then take the fiberglass screen we have now and staple that to the under side of the joist to help hold the insulation up there. A 6 mil poly down on the ground will help some and let the whole thing open under there dont close it up tight.

ED ;)

It's only open on either side of the room with a framed lattice piece. There is concrete block faced with shingle siding on the front. So I should start with fresh insulation, but the screening up and then leave the lattice piece as is to allow air to circulate?

Thanks for your help. It is nice to have advice before jumping in.

Yes both end open will work out just fine. :D

ED ;)