Firewall

I'm switching from A/C to non-A/C. The blower motor is much smaller on a non-A/C car. I've seen postings on this site where others have done the same using two methods. First is cutting the section of the firewall that holds the heater box and blower motor and welding a new one in. Second is making a patch panel to cover the old, larger hole for the blower. I'm asking if anyone has a stripped car ('73), would they be willing to cut out that small section of firewall ? If you can help, please send a picture and a price. Thanks, Keith.