Hi Mark,
Sorry to hear about your filter problem. What brand did you use? When I changed mine out, I used a NAPA Gold 1361. It's about an inch longer than the one I replaced. I haven't had any leakage since. When I went to get it I ran into the same problem about no listing. I instead looked up a filter for a 1982-87 Nissan Pulsar because they have a very similar looking engine to the PAO only with larger displacement. That reference might help you with your air filter problem as well. Owning one of these cars is a real learning experience. I've had mine since January of this year and it really has been a lot of fun at cruise nights and car shows. Always run the 91 octane no ethanol fuel in it. your carb will last much longer.
I know you guys got hit pretty hard by that snow storm last weekend, so that probably put an end to going for a ride any time soon.
Take care,
Mark