[rockybooth]

In cleaning out the basement to bring out my older system, I have come across some old (30-45 years) cartridges, and I have lost recollection of each of their strength and weaknesses.  Also a couple are damaged, and getting them repaired is probably expensive - perhaps more than purchasing a new cartridge of equal or better quality:
Decca - Red body and base, deep blue front.  No other ID other than SN. Looks very similar to Decca Mk-V seen on ebay.
Signet mk111E (diamond tip missing)
Grado, black and silver body. No other markings. Stylus end missing (another instance of the cleaning lady cleaning the turntable and snagging the tip)
Dynavector 20A
Ortofon SL-15E Mk. II

Questions:
1. How do you usually adapt to cartridges that have smaller diameter pins than the tonearm wiring ends? I do not want to crimp as I would probably sometime go back to the larger pins on another cartridge?
2. The Grado and Signet both needs service.  Given what I have available (the Ortofon is currently mounted) which of the Ortofon, Dynavector 20A, and the Decca, might be worth mounting and trying, given that they are all >30 years old.  This is important to know as the Premier arm is mounted in a Sota Sapphire and it is difificult to move to take into a store to get the cartridge changed and dialed in.  My finger agility was ok 70 years ago, but not up to the challenge today. 
Comments are greatly appreciated.

[theseeker]

go ahead and gently crimp the headshell leads onto the pins. but get something like this first:

https://www.mscdirect.com/browse/tnpla/06498802?cid=ppc-google-New+-+Hand+Tools+-+PLA_sabKvbrb9___164124448766_c_S&mkwid=sabKvbrb9%7cdc&pcrid=164124448766&rd=k&product_id=06498802&pgrid=35979537326&ptaid=pla-468571137761&gclid=CjwKCAiAgJWABhArEiwAmNVTB3qBqEHwVzvIbQCfG9IFDDhkJmQcGUkBOuXrP0t4FnNgTVOcGeJ8vBoCs08QAvD_BwE

after you're done using the cartridge with the smaller pins and you want to make them larger again, you can insert this pick tool into the leads and carefully pry them apart. it works very well, is an easy process, and i've done it many times without incident.

[audio.bill]

An easy to implement tip when needing to tighten the cartridge clips to securely fit the connection pins of a cartridge is to insert a round toothpick into the clip before attempting to crimp it. Only crimp very gently but the toothpick will help prevent over crimping which can crush and damage the clip. You shouldn't need to crimp it too much, only very slight changes in the size of the clip should be effective in achieving a secure fit. Hope this tip is helpful, it's saved me many times over the years.

[/mp]

In cleaning out the basement to bring out my older system, I have come across some old (30-45 years) cartridges....Grado, black and silver body. No other markings. Stylus end missing....

Swapping Grado styli is trivial. All but the most ham fisted should have no difficulty.
I bought my first Grado cartridge in the late 70s. Rummaging through my old cartridge collection, I found what are probably a ZFC+, Signature 8MZ & Prestige Black. Didn't find any of the F or G series.  New metal/plastic bodied Grados look the same as my old ones. Bet your Grado looks a lot like these:
https://gradolabs.com/cartridges/prestige-series-2
https://gradolabs.com/cartridges/prestige-series-specialty-cartridges
Some of them have the model name on the forward facing surface; some of them don't. Some of them use colored dots on the interchangeable stylus brackets; some of them don't. I have a recollection the Grado website had a page listing which colored dots indicated which model. I can't find it now. Maybe take a photo & email Grado.

Hope this (belatedly) helps,