I have an idea but I need to attach pup to pickguard...

TV Jones.

Peavey T40.

Fender WRHB.

Any guitar pickup you like.

 

Guitar pickups work just fine for bass, provided the overall string spacing is narrow enough.

 

Help if we knew what pickup so suggestions could be made. There’s a few pickup profiles out there. It’s not a one size fits all.

 

I am pretty sure the Rick neck pickup is pickguard mounted.

 

There are no inherent differences between guitar and bass pickups other than form factor. They both work on the electro-magnetic principle, and are fairly rudimentary devices. Regardless of what the marketing people will tell you, they’re the same, and will work fine, provided (as I mentioned) the overall string spacing is covered, which you already checked.

Having said that, there are many choices for aftermarket bass pickups and aftermarket guitar pickups, with a wide variety of baked-in tones. When selecting guitar pickups for bass duty it’s best to avoid the “overwound” or “hot” varieties, as they sacrifice response in the highest and lowest frequencies in order to gain output in the mid-frequencies.

I’ve personally had great results using the Wilde L90 for bass. They’re very affordable too!

 

Yeah you could use a blade type humbucker. Get a 4-wire one though. Guitar pickups can be very mid-rangey, and you'll have the option of wiring it in parallel.

I presume you are making your own pickguard... The other option is to mod a bass pickup so it can be mounted through a pickguard. A soapbar would be easy. Simply glue it to a piece of flatwork. A strip of aluminium would be ideal. You can drill and tap it for mounting screws. The existing hole in the corners of the soapbar could be filled with resin. Or even just glue short screws in there so the empty holes don't look out of place.

As for a Jazz or stingray pickup cover, you could easily pare back the ears with a sharp chisel and then also glue it to a flat bar for mounting.